REPORT 

OF  THE 

CHIEF  ENGINEER 

OF  THE 

New  York  &  Brooklyn  Bridge, 

JANUARY  1,  1877. 


BROOKLYN: 
EAGLE  PUINT,  34,  36  A  3S  FDMON  STREET. 


IE*  ICthrts 


SEYMOUR  DURST 


When  you  leave,  please  leave  this  hook 

Because  it  has  heen  said 
" £ver'thing  comes  t'  him  who  waits 

Except  a  loaned  hook." 


Avery  Architectural  and  Fine  Arts  Library 
Gift  of  Seymour  B.  Durst  Old  York  Library 


REPORT 


OF  THE 


CHIEF  ENGINEER 


New  York  &  Brooklyn  Bridge, 


January  i,  1877. 


BROOKLYN: 

EAGLE  PRINT,  34,  36  &  38  FULTON  STREET. 


1 

Digitized  by  the  Internet  > 

Archive 

in  2013 

http://archive.org/details/reportofchiefengOOroeb 


REPORT 

OF  THE 

CHIEF  ENGINEER. 


To  Hon.  Henry  C.  Murphy,  President  Board  of  Trus- 
tees of  the  New  York  and  Brooklyn  Bridge  : 
Sir  : — 

I  beg  leave  to  submit  herewith  my  report  for  the  year 
ending  1876,  and  as  no  report  was  made  of  last  year's 
operations,  that  will  also  be  included. 

The  amount  of  work  that  has  been  done  during  the 
past  two  years  is  so  great,  and  of  such  varied  character, 
in  order  fully  to  describe  all  the  operations  gone  through 
with  and  do  full  justice  to  all  the  details,  I  will  include 
with  this  the  full  reports  of  my  assistants,  each  one  giv- 
ing detailed  account  of  the  operations,  that  were  con- 
ducted under  his  direct  supervision. 

As  the  work  is  all  the  time  in  progress,  most  of  my 
time  is  taken  up  in  arranging  for  the  immediate  con- 
duct of  operations,  hence  these  remarks  will  be  concise. 

MASONRY. 

Both  towers  and  anchorages  have  been  completed  as 
far  as  may  be,  during  this  time.  The  small  quantity  yet 
remaining  to  be  put  on  tlie  anchorages  and  towers  can- 
not be  laid  until  the  cables  are  completed.  Much  of  the 
material  for  this  purpose  is  on  hand. 


4 


In  all  suspension  bridges  the  masonry  usually  forms 
about*  one-half  of  the  total  work  to  be  done.  We  may 
therefore  congratulate  ourselves  that  we  have  this  much 
behind  us. 

The  work  henceforward  will  be  of  an  entirely  different 
character.  Our  towers  and  anchorages,  as  they  stand,  chal- 
lenge comparison  with  any  masonry  in  the  world,  as  re- 
gards solidity,  the  material  of  which  they  are  built,  and  the 
careful  manner  in  which  that  material  was  laid,  and  con- 
sidering the  great  height  to  which  most  of  these  stone 
had  to  be  raised,  it  was  done  at  a  minimum  cost  and  a 
great  rate  of  speed,  the  only  delays  experienced  being 
caused  by  want  of  stone.  These  delays  are  not  to  be 
wondered  at,  when  it  is  remembered  that  the  stones  used 
were  cut,  over  six  hundred  miles  away,  and  gathered 
from  at  least  twenty  scattered  quarries,  with  boisterous 
seas  intervening  between  them  and  the  place  of  delivery. 
Out  of  the  thousands  of  ship  loads  of  stone  sent,  only 
one  was  lost. 

The  machinery  for  delivering  the  stones  on  top  of  the 
towers  was  so  adequate  that  it  cost  no  more  per  yard  to 
lay  the  top  courses  than  the  bottom  ones.  This  implies 
something,  when  it  is  borne  in  mind  that  the  summit  of 
the  New  York  tower  is  345  feet  above  the  foundation. 

TOWERS. 

The  arches  of  the  Brooklyn  tower  were  completed  in 
the  spring  of  1874.  The  line  of  thrust  in  these  pointed 
arches  falls  about  two  and  a  half  feet  outside  of  the 
centres  of  the  side  shafts  at  the  floor  line,  but  the  main 
outer  cables,  when  drawn  in  laterally,  modify  its  posi- 
tion to  such  an  extent  as  to  throw  it  six  inches  inside  of 
that  point ;  a  condition  of  the  utmost  stability. 

The  keystones,  huge  blocks  weighing  11  tons,  were 
fitted  in  without  trimming,  just  as  they  came  from  the 
quarry,  showing  that  the  thickness  of  joints  between  the 


5 


voussoirs  was  regulated  with  the  proper  accuracy  as  the 
arch  was  built  up. 

On  completion  of  the  tower,  heavy  castings,  compris- 
ing the  saddles  and  saddle-plates,  were  raised  at  a  single 
lift,  and  with  great  despatch,  and  hoisted  into  place 
without  any  mishaps.  In  general  form  they  do  not  dif- 
fer materially  from  those  used  on  the  Cincinnati  Bridge, 
except  that  they  are  about  twice  the  size. 

The  diameter  of  the  saddle-rollers  is  3^  inches.  Roll- 
ers of  larger  diameter  would  be  too  sensitive,  which  is 
not  desirable.  Rollers  of  smaller  diameter  would  be  too 
sluggish.  The  length  and  number  of  the  rollers  are 
properly  proportioned  for  the  load  resting  upon  them. 

It  is  not  expected  that  these  saddles  will  move  under 
any  passing  load  after  the  Bridge  is  completed.  The 
varying  strains  will  be  amply  resisted  by  the  mass  of  the 
tower;  but  during  the  construction  of  the  Bridge,  the 
saddles  are  sure  to  move.  The  direction  and  extent  of 
this  movement  are  somewhat  uncertain.  We  have  no 
precedent  just  like  this  bridge,  nor  any  data  on  which 
to  base  accurate  calculations.  I  have  placed  the  saddles 
12  inches  back  from  the  centre  towards  the  land  sides, 
a  position  where  we  will  be  on  the  safe  side,  no  matter 
what  the  movements  may  be. 

Besides  the  reception  of  the  main  cables,  the  saddles 
had  to  be  arranged  for  the  making  of  the  individual 
strands  above  them.  They  also  serve,  together  with  the 
plates,  to  hold  a  number  of  overfloor  stays,  which  are  30 
in  number,  on  each  side  of  the  towers.  The  bulk  of 
these  stays  will  be  secured  to  large  irons,  a  double  tier 
of  which  have  been  built  into  the  masonry  underneath 
the  saddle-plates,  extending  entirely  through  the  tower. 

ANCHORAGES. 

For  the  details  of  these  massive  pieces  of  masonry,  I 
would  refer  to  the  annexed  report  of  Mr.  Collingwood. 


6 


The  obstacles  met  with  in  the  progress  of  the  work 
are  there  fully  detailed.  The  great  weight  and  size  of 
all  the  materials  handled  required  apparatus  of  the 
strongest  kind,  combined  with  constant  exercise  of  care 
and  judgment. 

The  light  timber  foundations  are  in  each  of  the  an- 
chorages located  below  the  fresh  water  level,  thus  insur- 
ing their  permanent  preservation. 

ANCHOR  PLATES. 

Before  alluding  to  the  reasons  which  govern  the  de- 
signs for  the  plates,  the  chains,  and  some  of  the  other 
arrangements,  I  will  mention  that  the  resistance  offered 
by  the  weight  of  the  masoniw  on  the  plates,  against  the 
upward  pull  of  the  chains,  affords  a  margin  of  safety  of 
2%  times.  This  figure  may  appear  small  when  compared 
with  the  main  cables,  where  the  margin  of  safety  is  six 
times,  were  it  not  that  the  conditions  are  essentially  dif- 
ferent. In  the  case  of  the  cables,  we  have  to  provide  for 
numerous  contingencies  which  cannot  occur  in  the  an- 
chorage. For  instance,  allowance  must  be  made  for  the 
deterioration  of  the  wire  by  the  elements,  for  any  possi- 
ble imperfection  in  the  manufacture  of  the  cables,  for 
any  increase  in  weight  or  strain  over  that  first  contempla- 
ted, which  is  most  always  the  case,  and  lastly,  a  certain 
margin  is  required  so  as  not  to  strain  the  wire  beyond  its 
limit  of  elasticity. 

In  the  anchorage,  however,  we  have  only  two  factors 
to  deal  with— granite  and  gravity.  The  first,  a  material 
whose  very  existence  is  a  defiance  to  the  "  gnawing  tooth 
of  time  the  second,  the  only  immutable  law  in  nature; 
hence,  when  I  place  a  certain  amount  of  dead  weight,  in 
the  shape  of  granite,  on  the  anchor  plates,  I  know  it  will 
remain  there  beyond  all  contingencies. 

In  the  anchorage  plates,  which  are  huge  spider-shaped 
castings,  two  alternative  designs  were  possible.  Either 


7 


to  make  them  in  one  solid  casting,  or  to  di- 
vide each  casting  into  a  number  of  separate  thin 
plates  between  which  the  chains  would  be  inserted,  the 
whole  being  united  by  wrought  iron  bars,  as  proposed  by 
Mr.  Allen.  Castings  in  large  masses  seldom  show  the 
same  rate  of  strength  which  the  same  metal  will  give 
with  a  small  sectional  area  ;  but  it  was  found  easily  prac- 
ticable to  keep  the  greatest  thickness  of  metal  in  these 
plates  within  three  inches,  and  as  every  other  advantage 
remained  with  the  single  casting,  the  latter  plan  was  car- 
ried out  with  perfect  success.''  The  thickness  of  metal 
and  the  distribution  of  the  various  parts  of  these  cast- 
ings also  guarantee  the  absence  of  internal  strains. 

ANCHOR  CHAINS. 

The  anchor  chains  are  so  disposed  as  to  form  the  quad- 
rant of  a  circle  extending  from  a  point  26  feet  above 
the  anchor  plate,  to  which  they  are  joined  by  a  vertical 
section,  to  within  25  feet  of  the  front  of  the  anchorage, 
the  cable  itself  emerging  eight  feet  below  the  top  of  the 
masonry.  This  distance  of  25  feet  is  necessary  in  order 
to  compress  the  spreading  strands  of  the  cable  within 
their  proper  bulk,  before  emerging  from  the  masonry. 
In  the  arrangement  of  these  chains,  various  conditions 
and  conflicting  requirements  had  to  be  fulfilled.  The 
chief  point,  governing  all  the  others,  was  a  proper  attach- 
ment of  the  end  of  the  chain  to  the  strands  of  the  cable. 

In  all  previous  wire-cable  bridges,  each  cable  was 
composed  of  seven  strands.  This  division  was  impossible 
here,  as  the  strands  would  be  too  bulky  to  handle,  and 
could  not  be  properly  laid  tip,  when  exceeding  a  certain 
diameter.  The  next  number  of  strands  giving  an  ap- 
proximation to  the  figure  of  a  circle  is  thirteen,  but  here 
the  strand  was  still  too  large,  for  the  reasons  above 
given,  so  that  nineteen  strands  were  finally  determined 
on. 


8 


These  required  38  bars  at  the  ends  of  the  chains  for 
their  attachment.  The  bars  are  arranged  in  four  tiers, 
thus  occupying  a  minimum  amount  of  space — the  attach- 
ment being  further  made  in  such  a  manner,  and  in  such 
order,  that  the  strands  will  lie  comformably  to  the  cir- 
cular arrangement  in  the  saddles  on  the  towers,  and  at 
the  same  time  permit  each  new  strand  to  be  made  on  the 
end  of  the  chain,  so  as  not  to  be  interfered  with  by  the 
strands  already  in  place. 

The  next  question  was  the  choice  of  material ;  whether 
to  use  iron  or  steel  for  these  bars.  During  a  visit  at  Mr. 
Krupp's  works,  in  Essen,  during  the  year  of  1867,  the 
managers  obligingly  forged  for  my  inspection  an  anchor 
bar  2x9,  but  would  not  guarantee  any  greater  strength 
than  80,000  lbs.  per  square  inch  of  that  section  of  steel. 
A  subsequent  comparison  of  relative  rates  of  strengths 
and  prices  soon  showed  that  iron  would  have  the  prefer- 
ence over  steel. 

Iron  has  been  used,  and  I  think  the  choice  a  wise  one. 
To  build  up  an  iron  chain  of  such  dimensions  in  one  flat 
tier,  as  had  been  previously  the  practice,  was  also  impos- 
sible. Not  only  would  such  a  chain  have  been  12  feet 
in  width,  but  a  tight-fitting  pin  of  that  length  would 
have  to  be  driven  through  40  eye-holes — a  problematical 
proceeding  in  any  event,  independently  of  the  fact  that 
the  width  of  the  anchor  walls  would  not  admit  of  the 
driving  of  so  long  a  pin.  These  difficulties  were  over- 
come by  building  up  the  chains  in  two  separate  tiers, 
one  on  top  of  the  other,  and  separated  by  the  proper 
knuckle  plates.  At  one  point  these  chains  are  united  by 
thrust  and  tie  bars,  so  as  to  counteract  any  evil  results 
that  might  follow  from  attaching  one-half  of  the  cable 
to  the  lower  tier,  before  the  upper  tier  is  subjected  to 
any  strain. 

As  regards  the  section  of  the  chain  at  various  points, 
we  find  that  its  curved  position  reduces  the  strain  from 
the  cable  to  the  plate  about  one-third,  which  is  due  to 


9 


friction  of  the  link  heads  on  the  knuckle  plates.  It  is 
also  almost  certain  that  the  adhesion  of  the  chains  to  the 
cement,  and  the  hold  they  have  in  the  masonry,  reduces 
this  strain  nearly  one-third  more,  though  it  was  not 
deemed  expedient  to  take  any  account  of  this  additional 
safety,  in  calculating  the  size  of  the  plates  and  chains. 

The  change  in  section  of  chain  area  is  accomplished 
by  gradually  increasing  the  size  of  the  bars,  as  well  as 
their  number.  The  increase  in  number  being  required 
for  the  compact  and  symmetrical  arrangement  of  the 
strand  shoes  at  the  end  of  the  chain. 

PRESERVATION  OF  THE  ANCHOR  CHAINS. 

The  preservation  of  the  anchor  chains  from  rust  is  ef- 
fected in  the  manner  customary  on  previous  works,  by 
properly  painting  the  chemically-cleaned  surface  of  the 
iron  and  then  embedding  the  chain  in  hydraulic  cement. 
The  preservative  qualities  of  hydraulic  cement  have 
been  well  tried  by  long  experience. 

When  the  old  Pittsburgh  Aqueduct  was  dismantled,  a 
few  years  since,  the  anchor  chains,  after  sixteen  years  of 
service,  were  found  in  a  perfect  state  of  preservation. 
This  fact  was  again  corroborated  in  the  case  of  the  an- 
chorage of  the  Niagara  Bridge,  by  an  inspection  made  at 
the  instance  of  the  Canadian  government  two  years  ago, 
after  having  been  immersed  in  water-bearing  strata  for 
22  years. 

In  European  suspension  bridges  the  chains  are  usually 
carried  in  tunnels  open  to  access,  which  are  confidingly 
left  to  the  care  of  future  generations,  and  this  trust  is 
not  betrayed.  This,  however,  is  contrary  to  the  genius 
of  the  American  people ;  with  whom  everything  has  to 
look  out  for,  and  take  care  of  itself ;  hence,  in  the  arrange- 
ment of  this  anchorage  the  chains  are  inaccessibly  pre- 
served, and  are  not  intrusted  to  the  neglect  of  posterity. 

I  may  say  in  this  connection,  that  after  eight  years  of 
observation,  I  am  convinced  that  the  rusting  power  of  tbe 


10 

Brooklyn  air  is  fully  twenty-fold  greater  than  the  air  of 
localities  in  the  interior,  Cincinnati,  for  instance,  where 

the  smokr -impregnated  atmosphere  is  an  ample  protec- 
tion of  itself. 

CABLE  WORK. 

The  main  cables  consist  of  19  strands.  These  strands 
are  not  made  on  land  and  hauled  across  the  river,  but 
are  laid  up  in  place ;  and,  as  they  cannot  be  made  in 
the  position  which  they  are  finally  to  occupy  in  the  cable 
itself,  each  separate  strand  is  laid  up,  60  feet  above  this 
position. 

By  doing  this  we  gain  not  only  the  advantages  of  the 
strand  being  out  of  the  way  of  those  already  made,  but 
also  of  laying  up  each  wire  under  a  strain  of  400  pounds, 
thereby  testing  it  to  a  certain  extent  throughout  its  whole 
leno-th,  and  eliminating  all  bends  or  crooks.  Moreover, 
the  regulation  of  the  tension  could  not  be  accomplished 
in  the  low  position. 

A  uniform  tension  is  secured  by  giving  each  wire  the 
same  deflection.  This  work  is  done  by  men  called  "regula- 
tors" stationed  on  light  platforms  called  "  cradles,"  in 
the  centre  of  the  main  span,  and  each  of  the  land  spans. 
An  intermediate  set  of  cradles  is  also  provided  in  the 
main  span  for  the  better  control  of  the  wire  between  the 
towers  and  the  regulators,  so  that  in  all,  10  cradles  are 
required  ;  whereas,  one  sufficed  in  previous  works. 

After  being  oiled,  and  the  ends  joined  together  by 
steel  ferrules,  the  wires  are  wound  up  on  large  drums  at 
one  of  the  anchorages,  and  are  thence  transported  across 
the  river,  two  at  a  time,  by  an  endless  "  working-rope." 
This  rope  is  propelled  forwards  and  backwards  by  an 
engine  and  a  driving-wheel,  and  carries  a  "  traveling 
sheave"  upon  which  the  wires  run. 

When  a  set  of  strands  is  completed,  they  are  detached 
from  their  temporary  fastening  at  the  anchorage  by 
means  of  powerful  tackle,  let  forward  to  the  permanent 


11 


fastening  at  the  end  of  the  chains,  and  also  lowered  into 
the  saddles  on  the  towers  to  their  proper  place  in  the 

cable. 

All  four  cables  are  made  simultaneously.  After  the 
first  12  of  the  19  strands  are  completed  and  regu- 
lated, seven  of  them  are  compressed  together  to  form 
a  centre  core  around  which  the  remaining  strands  are 
afterwards  placed,  and  the  whole  continuously  wrapped 
with  wire. 

The  cables  are  made  about  five  or  six  feet  above  the 
position  they  will  occupy  after  all  the  settling  has  taken 
place.    This  settling  is  due  to  the  following  causes  : 

First,  the  deflection  due  to  the  load.  This,  for  steel 
wire,  would  be  at  the  rate  of  T-o  oWo  °f  a  ^oot  Per  f°ot 
length,  per  gross  ton  of  strain  per  square  inch  of  section. 

Secondly,  an  allowance  must  be  made  for  any  forward 
movement  of  the  saddles.  The  uplifting  action  of  the 
stays  in  the  quarters  will  also  cause  a  depression  in  the 
centre  of  a  little  more  than  two  feet. 

Lastly,  changes  of  temperature  must  be  provided  for, 
so  that  the  floor  cannot  fall  below  the  limit  fixed  by  law. 

The  length  of  time  required  to  make  the  main  cables 
is  largely  dependent  on  the  wind  and  weather,  and  will 
require  no  less  than  or  three  years.  This  estimate  of 
time  is  based  on  the  experience  at  Cincinnati,  where  it 
took  nine  months  to  lay  upa  million  ofpoundsof  wire  into 
cable.  According  to  that  it  would  take  six  times  nine 
months  for  the  cables  here  ;  but  by  making  two  pairs  of 
cables  at  once,  we  reduce  this  to  three  times  On  the 
other  hand,  our  bridge  is  two  and  a  half  times  as  long  be- 
tween anchorages  as  at  Cincinnati,  and  the  interruption 
from  wind  will  be  fully  twice  as  great.  This,  again,  is 
offset  by  the  fact  that  our  wire  here  being  a  larger  size,  we 
can  lay  up  a  greater  bulk  in  weight  in  the  same  length 
of  time.  Taking  all  these  things  into  consideration,  we 
see  that  the  above  estimate  of  time  is  correct. 


12 


Preparations  for  the  commencement  of  cable-making 
have  been  going  on  for  two  years  past,  during  which 
time  the  required  machinery  for  running  out  the  wire 
from  the  Brooklyn  anchorage  has  been  put  up,  and  is 
only  awaiting  the  completion  of  the  foot-bridge  for  an 
active  commencement. 

The  cradles  are  supported  by  heavy  wire  ropes,  sus- 
pended at  such  a  deflection  that  the  main  strands,  while 
being  made,  hang  directly  opposite  the  "  regulator,"  thus 
giving  him  every  facility  for  handling  the  wires.  Access 
is  had  to  the  "  cradles  "  by  means  of  a  light,  temporary 
foot  bridge. 

Two  designs  were  made  for  this  foot-bridge ;  one 
in  a  low  position,  at  the  level  of  the  floor  of  the  main 
bridge  ;  the  other  60  feet  above,  at  the  level  of  the  cra- 
dles and  strands.  Both  positions  have  their  advantages 
and  disadvantages.  From  the  low  foot-bridge  the  regu- 
lating of  the  strands  in  the  cables  can  be  easier  accom- 
plished, but  access  to  the  cradles  could  only  be  had  by 
means  of  long,  vertical  rope  ladders,  difficult  and  danger- 
ous to  climb.  The  intermediate  cradles  would  have 
been  almost  inaccessible.  Provision  for  safety  against 
storms  could  perhaps  be  equally  well  made  in  both  cases. 
The  upper  position  involves  much  heavier  strain  in  the 
ropes,  but  the  putting  in  place  could  be  more  easily  ac- 
complished. The  important  consideration  which  led  to 
the  adoption  of  the  high  position  was  the  accommodation 
of  the  shipping,  since  the  low  foot-bridge  would  have  at 
once  formed  a  barrier  across  the  river  at  a  uniform 
height  of  150  feet  above  the  water,  whilst  the  upper  po- 
sition gave  210  feet  height ;  which  head-room  would  be 
maintained  for  a  year  or  more,  when  the  lowering  of  the 
cable  strands  would  slightly  curtail  it. 

ROPES  ACROSS  THE  RIVER. 
A  general  plan  for  getting  the  ropes  across  the  river, 
and  suspending  them,  was  sketched  out  some  years  ago, 


13 


and  has  been  successfully  carried  out.  It  consisted  mainly 
in  laying  the  lighter  ropes,  including  a  "  carrier  rope,"  in 
the  bed  of  the  river,  from  which  they  were  raised  over 
the  towers  by  engines  located  on  each  side.  All  the 
heavier  ropes  were  then  taken  across  on  the  "  carrier 
rope "  by  means  of  carrier  sheaves,  and  after  being 
hauled  taut,  were  fastened  to  irons  secured  in  the  ma- 
sonry of  the  anchorage.  But  little  delay  was  caused  by 
the  passing  vessels,  notwithstanding  the  fact  that  the 
East  river  is  one  of  the  most  crowded  rivers  in  the  world 
and  that  no  less  than  a  hundred  craft  often  pass  the  line 
of  the  Bridge  during  an  hour. 

The  taking  over  of  the  first  heavy  rope  of  course  sug- 
gested many  improvements,  which  greatly  facilitated 
the  work  of  getting  over  the  remaining  ropes. 

FOOT-BRIDGE  FLOOR. 

The  platform,  or  floor,  of  the  foot-bridge,  3^  feet 
wide,  is  composed  of  wooden  strips  with  a  small  space 
between  them,  laid  on  top  of  the  ropes.  No  suspenders 
are  used.  To  protect  such  a  frail  structure  against  the 
violence  of  terrific  gales,  that  rage  here  almost  weekly,  is 
no  easy  task,  and  I  venture  to  predict  that,  notwithstand- 
ing every  precaution,  our  temporary  works  will  be  disa- 
bled mure  than  once  before  we  have  completed  cable 
making.  The  principal  security  against  the  wind  is  a 
pair  of  inverted  storm  cables,  assisted  by  a  number  of 
"  underfioor  stays  "  in  the  main  span.  In  the  land  span 
the  guys  lead  directly  to  anchorages  in  the  ground.  In  ad- 
dition to  these,  the  ropes  are  secured  together  laterally. 

It  is  of  but  little  moment  how  much  the  cradles  may 
sway  about  in  the  middle  of  the  main  span,  but  all  great 
waves  must  be  checked  before  they  reach  the  towers 
where  alone  the  ropes  can  be  injured.  This  is  done  by 
the  "  underfioor  stays,"  and  by  securely  fastening  the 
ropes  to  the  masonry. 


14 


The  inverted  parabolic  storm  cables  serve  rather  to 
prevent  the  foot-bridge  being  carried  away  bodily. 

FOOT  BRIDGE  ROPES. 

As  the  difficult  work  of  getting  these  ropes  over  was 
more  directly  in  the  charge  of  Mr.  Farrington,  1  beg  to 
refer  the  reader  to  his  report,  which  will  be  found 
annexed.  An  ample  training  in  this  kind  of  business 
at  Cincinnati  and  Niagara  Falls  had  especially  fitted  him 
for  such  work,  and  it  is  to  his  care  and  judgment,  com- 
bined with  the  efficient  aid  rendered  by  Mr.  Martin  and 
Mr.  McNulty,  that  we  owe  the  success  of  those  danger- 
ous operations,  without  a  single  accident  or  loss  of  life 
up  to  the  present  time. 

For  a  full  description  of  the  steel-wire  ropes  I  would 
refer  to  the  specifications,  subjoined  hereto.  The  con- 
tract for  these  ropes  was  let  to  the  Chrome  Steel  Co.,  of 
Brooklyn,  E.  D.,  and  they  were  manufactured  by  the 
John  A.  Roebling?s  Sons  Co.,  of  Trenton,  New  Jersey. 

CABLE  WIRE. 

As  may  be  supposed,  the  question  of  the  main  cable- 
wire  has  formed  the  subject  of  much  reflection  and 
thought ;  especially  in  preparing  the  specifications  for 
the  same.  Tests  have  been  going  on  at  intervals  for  the 
past  six  years,  and  constantly  during  the  last  two  years. 

The  making  of  the  tests  was  entrusted  to  my  able  and 
efficient  assistant,  Col.  Paine,  and  were  carried  out  under 
my  own  immediate  supervision.  In  the  course  of  these 
experiments  Col.  Paine  has  elicited  many  new  and  in- 
teresting facts.  Samples  were  obtained  from  most  of 
the  principal  foreign  as  well  as  domestic  makers  of  steel 
wire,  comprising  all  the  various  grades  of  steel,  but 
especially  cast-steel,  and  these  samples  were  in  no  case 
especially  prepared  to  exhibit  any  extraordinary  qualities 


15 


but  were  the  ordinary  products  of  the  works,  and  made 
at  a  reasonable  cost. 

The  principle  which  served  as  a  guide  in  these  deter- 
minations, was  to  obtain  a  certain  rate  of  strength  for 
the  least  amount  of  money. 

It  was  discovered  at  a  very  early  day  that  a  compara- 
tively slight  raise  in  the  requirements,  for  instance,  rais- 
ing the  rate  from  160  to  170,000  or  180,000  lbs.  per  square 
inch,  made  a  much  larger  proportional  increase  in  the 
price;  whereas  a  reduction  of  the  rate  below  these  figures 
did  not  affect  the  price  very  much. 

It  was  from  the  full  data  obtained  from  these  exten- 
sive experiments  that  the  first  sketch  of  our  require 
merits  in  tests  was  built  up  This  was  then  modified  to 
suit  this  particular  case.  As  the  wire  specifications,  which 
are  appended  to  this  report,  go  very  fully  into  the  rea- 
sons which  led  to  these  different  conclusions,  little  is  left 
for  me  to  say  here. 

The  choice  of  the  particular  size  of  wire  selected 
proved  very  fortunate,  not  only  in  respect  to  cable-mak- 
ing, but  also  in  respect  to  the  making  of  the  wire  icself 
Had  a  coarser  size  been  taken,  it  would  not  have  been 
possible  to  develop  the  degree  of  strength,  and  the  in- 
creased cost  of  a  smaller  size  would  not  be  compensated 
by  any  other  advantage. 

The  gauge  of  the  wire  is  given  at  No.  8,  full  (Bir- 
mingham), which  means  anywhere  between  the  No.  7£ 
and  No.  8.  Every  practical  wire  drawer  knows  that 
wire  gauges  differ,  not  only  in  different  establishments, 
but  in  the  same  establishment,  and  that  they  constantly 
wear  out  and  get  larger.  To  avoid  this  trouble,  the 
weight  of  the  wire  has  been  fixed  at  14  feet  to  the  pound. 

The  first  thing,  therefore,  to  be  done  by  the  contractor, 
is  to  draw  some  wire  from  the  stock  he  proposes  to  use, 
until  he  gets  a  piece  of  exactly  sueh  a  weight ;  this  wire 
then  forms  the  standard  by  which  his  whole  product  is 
gauged. 


16 


It  is  evident  that  the  rate  of  strength '  per  square  inch 
is  entirely  governed  by  the  specific  gravity  of  the  ma- 
terial. Under  the  specifications  we  would  probably  have 
to  deal  with  every  variety  of  steel,  from  the  light  carbon 
steels  with  1-J  per  cent,  or  more  of  carbon,  down  to  Bes- 
semer, containing  often  less  than  one-fourth  per  cent.,  and 
from  that  to  the  still  heavier  Chrome  Steel.* 

In  order  to  embrace  all  of  these,  the  weight  is  fixed  at 
483. 84  lbs.  per  cubic  foot,  which  represents  the  rate  of 
160,000  lbs.  per  square  inch  for  wire  of  which  14  feet 
weighed  one  pound.  Now,  if  the  material  which  the 
contractor  uses  should  prove  lighter  than  the  figure  fixed 
above,  he  will  be  obliged  to  slightly  increase  the  diame- 
ter of  his  wire,  in  order  to  make  it  weigh  14  feet  to  the 
lb.  If  his  material  is  heavier,  the  reverse  will  be  the 
case.  The  effect  of  this  will  be  to  make  a  slight  change 
in  the  diameter  of  the  \yhole  cable,  and  also  in  the  rate 
of  strength  per  square  inch  ;  that  is,  it  will  give  a  lower 
rate  with  light  wire  and  a  higher  rate  with  heavier  wire; 
but  as  long  as  each  cable  contains  6,300  wires,  the  break- 
ing strength  of  each  one  of  which  is  fixed  at  3.400  lbs., 
it  is  impossible  that  any  variation  can  be  brought  about 
in  the  ultimate  strength  of  the  cables  /  and,  further,  as 
long  as  every  wire  weighs  14  feet  to  the  lb.,  it  is  impossi- 
ble that  the  total  weight  of  the  cables  can  be  changed  in 
any  way. 

While  I  am  discussing  this  question  of  ultimate 
strength,  I  will  say  it  is  a  matter  of  very  little  impor- 
tance to  me  whether  the  ultimate  strength  of  the  wire 
given  in  the  specifications  is  a  little  greater  or  little  less 
than  160,000  lbs.  per  square  inch.  The  ultimate 
strength  was  inserted  in  the  specifications,  because  it  is 
customary,  and  is  better  understood  by  the  wire  makers 
for  whom  these  specifications  were  written.    As  long  as 


•Average  weight  of  12  specimens  of  Chrome  Steel  as  given  in  the  Circular  of 
Chrome  Steel  Co.,  of  January,  !S74,-is  4SS.92  lbs.  per  cubic  foot. 


17 


I  am  sure  of  an  elastic  limit  of  1,600  lbs.,  and  that  the 
maximum  strain  on  each  wire  in  the  cable  will  be  of  about 
570  lbs.,  I  am  absolutely  safe  beyond  all  contingencies, 
even  if  every  wire  were  to  break  with  3,000  lbs.  strain. 

The  determination  of  the  ultimate  size  and  strength 
of  the  cables  is  governed  by  another  set  of  considerations 
of  a  different  character,  but  of  equal  importance.  They 
have  already  been  spoken  of  under  the  head  of  anchor 
chains. 

QUALITY  OF  WIRE. 

Throughout  this  whole  investigation  it  has  been  felt 
that  one  grave  difficulty  surrounded  the  question  of 
steel,  and  that  is.  lack  of  uniformity  of  quality.  This 
question  is  so  serious  that,  were  it  not  for  the  manifold 
advantages  to  be  obtained,  steel  would  not  have  been 
used. 

The  experience  gained  by  the  tests  made  at  the  Bridge, 
as  well  as  personal  experience  of  twenty  years  in  hand- 
ling thousands  of  tons  of  steel,  in  the  wire  rope  business, 
have  shown  that  all  steel  is,  within  limits,  very  uncer- 
tain in  its  character;  a  fact  applying  with  much  greater 
force  to  the  high  and  more  expensive  crucible  cast-steels 
than  to  the  other  medium  qualities. 

Even  with  the  best  intentions  on  the  part  of  the 
maker,  it  is  very  doubtful  if  successive  lots  of  any 
amount  will  turn  out  exactly  the  same.  In  a  private 
business  this  point  can  be  more  easily  settled.  The  rep- 
utation of  the  maker  would  be  the  leading  consideration  ; 
further,  the  price  has  something  to  do  with  the  quality  ; 
and  lastly,  as  the  amounts  of  steel  handled  are  usually 
small,  it  is  easy  to  change  from  one  maker  to  another  if 
the  steel  turns  out  badly. 

Such  a  course  is  manifestly  impossible  in  the  case  of 
a  work  of  the  magnitude  of  the  East  River  Bridge,  and 
least  of  all,  in  a  city  like  New  York.  What  then  was  to 
be  done  ?    To  invite  the  bidders  to  make  a  few  rings  was 

2 


■J  8 


well  enough  in  its  way.  It  would  serve  to  show  the  en- 
gineer what  the  bidder  could  do,  and  instruct  the  bidder 
as  to  what  had  to  be  done  ;  but  to  assume  that  a  few  rings 
would  be  a  sure  guaranty  for  the  whole  contract,  could 
not  be  thought  of. 

To  acquire  any  reliable  knowledge  as  to  the  uniformity 
of  any  maker's  product,  would  require  an  order  of  at  least 
50  tons,  and  by  the  time  this  was  distributed  among  all 
who  could  do  the  work,  it  would  amount  to  giving  out 
the  contract  piecemeal,  without  any  competition. 

The  plan  adopted  was,  therefore,  the  only  one  that 
could  be  practically  executed,  namely  :  to  invite  public 
competition  with  a  view  of  awarding  the  contract  to  the 
lowest  bidder,  and,  on  the  other  hand,  to  exact  a  large 
bond  for  the  faithful  performance  of  the  contract ;  and, 
finally,  to  secure  the  qualities  called  for  in  the  specifica- 
tions by  a  complete  system  of  tests.  The  assurance  of 
the  correct  performance  of  these  tests  must  remain  a  mat- 
ter of  confidence  and  trust.  The  building  of  the  whole 
Bridge  is  a  matter  of  trust. 

Among  other  questions  which  came  up  was  a  minor 
one  respecting  the  advisability  of  limiting  the  competi- 
tion to  wire  makers,  or  extending  it  to  the  whole  steel 
trade. 

My  views  on  this  matter  are  contained  in  the  follow- 
ing letter  addressed  to  my  assistant,  Colonel  Paine,  on 
Oct.  16th,  1876. 

"  Dear  Colonel  : 

Jn  your  letter  of  the  14th  you  inquire  whether  a  rigid 
adherence  is  expected  in  regard  to  that  item  of  the  cable- 
wire  specifications  which  excludes  all  but  wire  makers 
from  putting  in  bids. 

I  would  say  in  reply  that  there  are  many  weighty  consid- 
erations for  adhering  to  this  stipulation,  and  only  one  poor 
reason  for  not  doing  so;  the  latter  being  a  weak  desire  to 
please  everybody,  a  course  which  inevitably  ends  in  dis- 


19 


astrons  complications,  from  whieh  von  can  only  extricate 
yourself  by  great  effort  and  expense  of  time  and  money. 
All  of  which  can  easily  be  avoided  at  the  outset. 

In  the  first  place,  I  believe  it  to  be  an  accepted  fact, 
that  the  wire  maker  makes  wire ;  so  it  is,  therefore,  per- 
fectly natural,  that  in  our  specifications  we  should  call 
for  wire  makers  to  give  us  bids  ;  but  it  would  seem  very 
odd  if  we  should  invite  bids  of  a  man  who  has  an  ore- 
bed  or  a  coal  mine,  or  who  sells  pig  iron,  or  steel  ingots, 
or  blooms,  or  billets,  or  bars,  or  rods,  or  lumps  of  zinc. 
All  these  operations  culminate  in  the  final  product  of 
the  finished  wire  made  by  the  wire  maker.  He  is 
the  last  man  in  the  chain,  and  must,  of  necessity,  be  the 
one  who  fixes  the  market  price  of  wire. 

In  the  next  place,  if  a  wire  maker  should  get  this  con- 
tract, he  must  have  perfect  freedom  to  buy  his  steel 
wherever  be  pleases,  and  must  not  be  tied  down  to  the 
use  of  any  one  person's  product.  There  are  a  thousand 
steel  makers  in  the  world,  and  if  one  man's  steel  will  not 
answer,  another's  may.  He  can  thus  always  help  him- 
self if  his  wire  does  not  come  up  to  the  mark.  Parties 
who  are  not  wire  makers  will  only  bid  for  the  sake  of 
pushing  in  their  own  particular  brand  of  steel.  They 
will  take  good  care  that  it  shall  stand  the  preliminary 
tests,  even  if  they  have  to  buy  a  piece  of  steel  for  this 
purpose.  For  this  reason  I  attach  little  value  to  our 
preliminary  tests  as  a  sample  of  what  is  to  come. 

The  task  of  annulling  such  a  contract,  when  once 
made,  is  no  child's  play,  and  would  make  a  terrific  com- 
motion. If  we  tie  ourselves  down  to,  a  particular  steel 
this  contingency  is  almost  sure  to  happen,  but  if  the  wire 
drawer  can  use  any  steel  he  pleases,  this  contingency  can 
scarcely  arise. 

I  know  of  no  wire  drawer  who,  with  open  eyes,  will 
bind  himself  to  use  another  man's  steel  exclusively  ;  and 
it  is  for  this  reason  that  the  outside  gentlemen  are  so 


20 


anxious  to  put  in  independent  bids,  and  then  trust  to 
luck  to  get  somebody  to  draw  the  wire  for  them. 

For  seven  long  years  past  our  gradually  lising 
towers  have  warned  all  interested  parties  that  our  cable- 
wire  would  be  wanted  at  an  early  day,  and  now,  when  the 
time  has  come,  thev  are  not  readv,  but  want  to  hed^e 
around  in  some  irregular  way  to  get  an  advantage  over 
the  rest,  and  I  am  free  to  tell  you  that  I  shall  use 
my  utmost  influence  against  any  irregular  bid,  because  I 
look  upon  them  as  made  with  deliberate  attempt  to  get 
an  unfair  advantage  over  fair  and  square  bidders. 

I  can  give  no  better  illustration  of  the  foregoing 
points  than  by  referring  to  the  contract  for  Fridge 
ropes,  now  being  executed  at  Trenton  Here  were  a 
number  of  ropes  to  be  made  in  accordance  with  a  set  of 
strict  specifications,  but,  in  addition,  they  had  to  be  made 
out  of  a  particular  kind  of  steel,  and  these  two  conditions 
proved  antagonistic. 

Many  months  of  time  and  labor  were  expended  in 
vain  attempts  to  make  it  answer,  and  when  finally 
enough  had  been  squeezed  out  to  pass  the  tests  for  one 
or  two  ropes,  it  was  still  found  to  show  such  a  want  of 
uniformity,  and  be  so  full  of  inherent  defects,  as  to 
break  of  its  own  accord  when  laid  up  in  the  rope. 

Now,  here  was  material  which  was  manifestly  unlit  to 
be  put  into  ropes,  notwithstanding  it  had  passed  the 
tests  as  steel.  The  question,  therefore,  at  once  arose, 
should  we  go  on  and  make  poor  ropes,  and  remain  with- 
in the  letter  of  the  law,  or  throw  it  to  one  side  and  use 
a  material  suitable  for  the  purpose  I 

The  large  quantity  of  condemned  chrome  steel  now 
lying  in  the  mill  yard,  shows  which  way  this  decision 
went. 

I  need  only  say,  in  conclusion,  that  I  am  opposed  to 
any  bid  which  does  not  come  from  a  wire  maker  of  good 
reputation,  and  long  experience  in  making  steel  wire. 


21 


Our  great  necessity  is  for  steel  wire  of  perfect  uni- 
formity. If  a  wire  breaks  during  cable-making,  we 
always  lose  two  wires  of  the  whole  length  of  the  cables, 
valued,  say,  at  $10.  The  regulation  of  the  wires  back 
of  them  may  be  disturbed,  so  that  the  loss  of  time  is  in 
no  case  less  than  two  hours,  and  often  a  whole  day, 
during  which  time  nothing  can  be  done,  and  the  whole 
work  stops.  In  such  a  case  we  would  lose  from  two  to 
three  hundred  dollars. 

Very  truly  yours, 

W    A.  ROEBUNG." 

CABLE  WIRE  SPECIFICATIONS. 

At  the  time  these  cable-wire  specifications  were  written, 
I  supposed,  in  common  with  other  engineers,  in  fact  it 
was  in  accordance  with  all  the  tests  I  had  made  up  to 
that  time,  that  Open  Hearth  or  Bessemer  steel  could  not 
be  made  to  come  up  to  the  standard  required. 

The  whole  specifications  were  written  in  accordance 
with  these  views.  Bessemer  and  Open  Hearth  steels 
were  carefully  excluded,  and  only  crucible  cast-steel 
called  for,  and  the  specifications  were  so  submitted  to 
the  Trustees.  After  due  discussion  in  their  Board,  it 
was  decided  to  enlarge  the  field  of  competition,  by  re- 
ceiving bids  from"  all  kinds  of  steel  wire  makers,  and  not 
limit  them  to  crucible  cast  steel.  In  this  shape  the  spe- 
cifications were  put  before  the  public. 

After  the  issue  of  the  specifications,  three  months  of 
incessant  activity  ensued  among  such  wire  drawers  as  in- 
tended to  bid  on  the  work.  It  soon  became  manifest, 
from  samples  received,  that  both  Open  Hearth  and  Bes- 
semer steels  could  be  so  manipulated  as  to  meet  the  re- 
quirements in  every  respect,  giving  a  uniformity  equal 
to  and  even  superior  to  any  brand  of  cast-steel,  and  this 
could  be  done  not  only  in  a  few  specimen  rings,  but  in 
many  tons  at  a  time. 


22 


To  what  extent  this  may  be  due  to  the  making  of  the 
steel  or  to  the  drawing  of  the  wire  I  am  not  prepared  to 
say,  but  inasmuch  as  several  kinds  of  Bessemer  steel 
produced  nearly  the  same  results,  it  is  probably  largely 
due  to  the  wire  drawing. 

Now  this  is  a  very  important  fact,  not  only  in  its  bear- 
ing on  steel  wire  in  general,  but  particularly  its  effect 
on  the  cost  of  the  bridge  and  cables,  because  Open 
Hearth  or  Bessemer  wire  can  be  made  at  a  cost  approxi- 
mating one  half  the  price  of  good  cast-steel  wire,  and 
the  saving  of  two  or  three  hundred  thousand  dollars  is  a 
matter  of  no  small  moment  to  the  two  cities. 

It  was  supposed  at  the  time  of  writing  these  specifi- 
cations that  such  wire  as  was  called  for  could  not  be 
made  without  going  through  the  process  of  hardening 
and  tempering.  The  tests  of  the  final  sample,  however, 
showed  that  all  the  requirements  could  be  met,  without 
subjecting  the  wire  to  this  process.  This  is  largely  due 
to  the  size  of  wire  used,  and  has  resulted  in  a  consider- 
able diminution  of  the  amount  of  each  bid. 

STRAIGHTENING  THE  WIRE. 

In  regard  to  the  subject  of  straightening  of  the  wire, 
it  should  be  said  that  this  idea  was  perfected  by  Col. 
Paine  only  a  short  time  previous  to  the  issue  of  the 
specifications,  the  bulk  of  the  preliminary  tests  having 
been  made  with  ordinary  curved  wTire. 

As  the  difference  of  curvature  between  the  inside  and 
outside  of  a  ring  of  wire,  two  feet  in  diameter,  is  consid- 
erable, it  may  readily  be  supposed  that  the  metal  is  in 
different  conditions  of  strain,  on  the  two  respective  sides. 
The  elimination  of  such  strain  is  not  only  perfectly  ac- 
complished by  this  process  of  straightening,  but  it  in- 
volves other  results  of  great  importance.  Both  the  ulti- 
mate strength  and  the  limit  of  elasticity  are  raised  near- 
ly eight  percent.,  but  the  modulus  was  uniformly  found 
to  be  as  high  as  29,000,000. 


23 


If  time  had  allowed  of  making  the  experimental  tests 
solely  with  straight  wire,  the  modulus  would  have  been 
fixed  at  29,000,000  and  above,  instead  of  allowing  a  mar- 
gin, as  has  been  done.  The  apparent  anomaly  of  call- 
ing for  a  stretch  of  two  per  cent,  in  the  50  feet  lengths, 
and  3-J  per  cent,  in  the  5  feet  lengths,  where  the  reverse 
might  be  expected,  is  susceptible  of  an  easy  explanation, 
No  wire  under  strain  breaks  in  two  places  at  the  same 
time.  As  soon  as  the  strain  has  passed  the  limits  of  elas- 
ticity, weak  places  begin  to  develop  themselves  at  particu- 
lar points,  and  a  greater  portion  of  the  stretch  is  thenceforth 
confined  to  their  immediate  neighborhood,  and  not  dis- 
tributed over  the  whole  length  of  the  wire.  The  percent- 
age of  stretch  when  referred  to  the  long  length  must 
therefore  be  less  than  when  referred  to  the  short  length. 
This  also  explains  the  fact  why  the  same  piece  of  wire 
when  broken  a  second  or  third  time  will  exhibit  the  same 
or  often  a  greater  strength  than  when  broken  the  first 
time. 

APPROACHES. 

As  cable-making  will  be  under  fair  headway  by  next 
spring,  the  time  will  then  have  arrived  to  commence 
actual  work  on  the  construction  of  our  approaches. 

We  cannot,  of  course,  commence  on  the  whole  line  at 
once,  and  it  will  be  most  convenient  to  commence  at 
each  of  the  anchorages,  and  work  towards  the  termini. 

Last  spring  one  of  the  assistant  engineers,  Mr.  Ililden- 
brand,  was  instructed  to  make  several  alternative  designs, 
principally  in  reference  to  the  appearance  of  the  side 
elevation  of  the  New  York  approach.  He  also  made 
four  different  plans  for  the  bridge  across  Franklin  Square. 

As  the  side  elevations  will,  in  all  probability,  front  on 
an  important  street  in  New  York,  it  is,  perhaps,  fitting 
that  the  architectural  features  on  that  side  should  be  of 
a  better  character,  and  of  more  imposing  appearance 
than  on  the  Brooklyn  side,  where  the  approach  is  not  so 
much  exposed  to  view. 


24 


BROOKLYN  APPROACH. 
Commencing  at  York  street,  there  will  have  to  be 
erected  on  each  side  of  the  street  two  lofty,  substantial 
parallel  walls,  for  the  purpose  of  supporting  the  six 
u  plate-girders "  by  which  the  approach  crosses  York 
street,  in  an  oblique  direction.  Jn  order  to  adapt  the 
walls  for  future  use  in  forming  the  sides  of  buildings, 
they  wTill  be  provided  with  suitable  archways  to  serve  as 
doors  and  windows.  Where  Garrison  street  enters  York, 
a  wrought  iron  girder  must  be  thrown  across  the  end  of 
the  former,  as  a  support  for  the  main  girder  crossing 
York  street. 

The  space  of  ground  between  the  wall  on  York 
street  and  the  rear  of  the  anchorage  can,  of  course,  be 
occupied.  In  this  discussion  the  primary  object  of  this 
construction  should  not  be  lost  sight  of,  which  is  to  sup- 
port the  roadway  of  the  approach,  and  every  other  con- 
sideration must  be  subordinate  to  it.  Owing  to  the 
height  at  this  point,  such  support  can  only  be  in  the 
nature  of  columns  ;  either  isolated  iron  columns,  or  brick 
piers  connected  by  light  longitudinal  arches.  To  give 
the  necessary  lateral  support  to  such  columns  they  must 
be  enclosed  by  walls  with  substantial  buttresses,  which 
form  the  side  view7  of  the  architectural  drawings  now 
being  made.  These  remarks  apply  also  to  that  part  of 
the  approach  between  York  and  Main  streets,  though  it 
may  be  desirable  to  make  it  of  a  more  imposing  archi- 
tectural character,  or  similar  to  the  approach  on  the 
New  York  side,  described  further  on. 

As  soon  as  Main  street  is  passed  we  come  to  that  part 
of  the  approach  bounded  by  Prospect,  and  Main  streets, 
on  which  will  be  located  the  machinery  that  will  drive 
the  endless  ropes  for  the  trains  on  the  vail  road  tracks. 
Here  the  supports  must  be  arranged  to  suit  that  object. 
The  large  square  at  the  terminus  can  either  be  filled  up 
solid  with  earth  or  be  arranged  for  an  underground  depot 
or  station,  if  required. 


25 


I  do  not  think  it  advisable  that  we  should  at  once 
make  all  the  necessary  preparations  for  establishing  ware- 
houses under  this  approach,  but  confine  ourselves  to  what 
is  needed  for  support  merely. 

The  uses  to  which  these  spaces  can  be  put  are,  after  all, 
quite  limited.  The  incessant  rumbling  overhead  is  one 
serious  objection  to  them.  The  necessary  amount  of 
light  will  be  difficult  to  obtain.  No  chimneys  can  pierce 
the  roof,  but  must  come  out  on  the  outer  walls.  They 
could,  however,  be  heated  by  steam.  Many  other  objec- 
tions to  them  might  be  mentioned,  all  of  which  goes  to 
show  that  the  utilization  of  these  spaces  had  better  be 
left  until  the  approach  is  finished,  or  until  the  demands 
of  trade  indicate  clearly  what  is  required. 

To  commence  work,  therefore,  next  season,  it  is  neces- 
sary to  obtain  possession  of  the  following  property:  The 
property  on  James  street,  including  the  whole  of  the  tri- 
angular cluster  of  old  frame  buildings  bounded  bv  York 
James  and  Main  streets,  and  James  street  closed.  It 
will  also  be  necessary  to  purchase  the  north  corner  of 
Garrison  and  York  streets. 

NEW  YORK  APPROACH. 

This  approach  differs  in  many  particulars  from  that 
of  Brooklyn.  It  is  nearly  twice  as  long,  and  much 
more  elevated,  thus  involving  more  cost  and  labor 
in  construction.  Its  location  also  demands  more  of 
an  architectural  display  than  (ran  be  made  in  Brooklyn. 

The  property  between  the  anchorage  and  Franklin 
Square  we  own  already  and  it  gives  room  for  one  build- 
ing. The  location  is  very  desirable  for  business  purposes, 
hence  I  think  it  would  be  well  in  this  instance  to  adapt 
the  building  to  business  purposes  at  once,  and  the"  inner 
division  walls  as  well  as  the  outer  ones  can  be  construct- 
ed in  accordance  with  plans  made  for  that  purpose.  A 
portion  of  the  interior  of  this  building  can  also  be  de- 
voted to  stairways  for  the  purpose  of  gaining  access  to 


26 

the  top  of  the  anchorage,  whence  people  can  cross  the 
bridge  on  foot  or  take  the  horse  cars.  The  front  of  this 
building  on  Cherry  street  mast,  of  coarse,  consist  of 
heavy  walls  supporting  one  end  of  the  bridge  by  which 
the  approach  crosses  Franklin  Square. 

The  Franklin  Square  bridge  will  be  85  feet  wide  ;  195 
feet  long  at  the  north  end,  and  about  140  feet  long  at  the 
south  side.  Four  general  styles  of  structure  are  possi- 
ble at  this  point : 

First,  the  stone  arch. 

Second,  the  wrought  or  cast  iron  arch. 

Third,  a  girder  crossing  the  whole  span. 

Fourth,  a  girder  supported  in  the  middle  by  two 
cross  girders  resting  on  one  column  on  the  south  side, 
and  two  on  the  north  side.  This  arrangement  practi- 
cally divides  the  span  into  two  bridges,  one  over  Pearl 
street  and  the  other  over  Cherry  street. 

The  relative  cost  of  these  bridges  is  about  in  the  or- 
der in  which  they  are  enumerated.  The  stone  arch  will 
cost  about  five  or  six  times  as  much  as  the  others ;  the 
material  itself  is  costly,  the  abutments  would  be  extreme- 
ly massive,  and  contain  large  quantities  of  material, 
chiefly  because  the  foundations  have  to  go  down  as  low 
as  the  anchorage  in  order  to  insure  the  necessary  stabili- 
ty. The  heavy  centering  on  which  to  support  these 
arches  is  also  expensive,  and  would  tend  to  obstruct  the 
two  streets  These  same  remarks  would  apply  with  much 
less  force,  however,  to  the  iron  arches. 

A  continuous  girder  across  the  whole  span  is  cheaper 
than  the  two  previous  arrangements,  but  it  is  more  ex- 
pensive than  that  supported  by  the  columns.  The  length 
of  the  span  would  require  a  truss  of  sixteen  or  eighteen 
feet  in  height.  This  would  not  look  well  in  that  situa- 
tion, as  it  would  obstruct  the  view  up  and  down  the 
street  too  much ;  besides,  two  of  these  girders  on  the 
north  side  would  only  be  elevated  a  foot  or  two  above 
the  lowered  roof  of  the  building  between  Cherry  and 


27 


Pearl  streets,  which  would  look  odd — almost  absurd — in 
such  a  locality. 

The  last  of  the  four  plans  (which  might  be  called  the 
column  plan),  will  be  the  cheapest  and  will  also  look 
very  well.  This  calls  for  a  cast-iron  column,  or  rather 
cluster  of  columns,  at  the  point  between  Cherry  and 
Pearl  streets,  and  for  two  brick  piers,  to  be  erected  with- 
in the  walls  of  the  building  between  these  two  streets.  On 
these  supports  rest  two  transverse  wrought  iron  girders, 
which  latter  support  the  main  bridge. 

A  single  or  double  Warren  girder  about  nine  feet  in 
depth  will  make  the  best  kind  of  truss.  With  the  cen- 
tral support  it  can  be  calculated  as  a  continuous  girder, 
thus  requiring  a  minimum  amount  of  iron.  The  road- 
way of  the  bridge  will  rest  on  top  of  these  girders. 

The  stone  abutments  at  each  end  will  also  contain  less 
masonry  than  by  any  other  plan.  • 

The  bridges  over  all  the  other  streets  will  be  ordinary 
plate  girders. 

We  come  now  to  the  question  of  opening  a  street  par- 
allel to  the  south  side  of  this  approach. 

The  location  of  Frankfort  street,  with  reference  to  the 
approach,  is  such  that  it  of  itself  forms  such  a  street  for 
the  greater  part  of  the  distance.  In  any  way  that  the 
question  can  be  discussed,  the  inevitable  conclusion  is 
forced  upon  us  that  such  a  street  should  be  established. 
Even  outside  of  the  Bridge  question,  the  necessity  for 
such  a  street  is  apparent,  because  there  is  not  a  single 
wide  street  leading  from  the  vicinity  of  the  City  Hall 
straight  down  to  the  East  river,  below  2\Te\v  Chambers 
street.  The  extra  amount  of  property  required  is  but 
little.  One  or  two  lots  between  Franklin  Square  and 
Cliff  street,  and  a  portion  of  Burr's  building,  on  the  cor- 
ner of  Cliff  and  Frankfort  streets.  By  this  plan  the 
lower  end  of  the  present  Frankfort  street,  from  Cliff  to 
Pearl,  will  be  closed.  The  steep  grade  near  Vandewater 
street  can  also  be  diminished  to  the  exteut  of  two  or 
three  feet. 


28 


Respecting  the  question  of  an  alley  of  from  twelve  to 
sixteen  feet  wide  on  the  north  side  of  the  approach,  two 
points  have  to  be  decided.  If  the  property  underneath 
is  to  be  utilized  now,  then  this  alley  should  be  opened  at 
once  ;  but  if  not,  there  can  be  no  immediate  necessity 
for  it.  In  either  case  the  positions  of  the  lots  we  cut 
through  are  such  that  we  have  to  buy  half  the  land 
required*  for  an  alley. 

The  wall  on  the  north  side  of  the  approach  can  be 
made  of  a  plainer  character  than  that  on  Frankfort  street. 
Each  space  beneath  the  approach  will  be  included  within 
four  walls,  two  of  them  forming  the  principal  sides 
of  the  approach,  and  two  forming  the  abutments 
for  the  girders  across  the  streets.  Within  this  space 
suitable  supports  for  the  roadway  will  be  constructed. 
Estimates  are  now  being  made  to  determine  as  to  wheth- 
er iron  columns,  suitably  braced,  or  brick  piers  with  con- 
necting arches,  will  best  answer  the  purpose.  The 
supports  will  be  so  arranged  as  to  facilitate  the  division 
of  the  future  warehouses  into  stories. 

The  utilization  of  these  spaces  will  be  effected  at  a 
much  earlier  day  than  on  the  Brooklyn  side. 

In  order  to  illustrate  the  plan  of  brick  piers  and  arches, 
let  us  take  the  block  between  Cliff  and  Yandewater 
streets.  This  represents  a  rectangle  85  feet  wide  by  about 
250  feet  in  length,  and  surrounded  on  all  four  sides  by 
walls:  at  the  narrow  ends  by  the  abutment  walls,  and 
at  the  two  other  sides  by  the  main  walls  of  the  approach. 
Within  this  space  there  will  be  carried  up  three  or  four 
longitudinal  parallel  rows  of  brick  piers,  from  fif- 
teen to  eighteen  feet  apart,  and  connected  together 
by  light  flying  arches.  The  dimensions  of  the  piers 
at  the  base  would  be  about  six  feet,  and  tapering  off 
to  about  three  feet  at  the  summit  The  offsets  in 
the  piers  as  well  as  the  connecting  arches  can  be  made 
suitable  for  division  into  stories.   The  connecting  arches 


29 


will  be  only  about  eighteen  inches  in  thickness  at  the 
crown,  and  of  a  uniform  width  with  the  piers. 

The  top  will  be  covered  by  a  coping  of  stone  or 
cast-iron.  Laterally,  these  brick  piers  must  be  braced  by 
heavy  iron  beams,  twelve  or  fifteen  inches  deep.  These 
can  be  so  placed  as  to  serve  as  supports  for  the  floors  of 
the  different  stories. 

The  general  arrangement  above  described  comes  the 
nearest  to  being  fire-proof  of  any  that  can  be  devised, 
although  it  may  prove  a  little  more  expensive  than  that 
with  iron  columns  alone. 

The  roof,  in  any  case,  will  be  formed  by  laying  iron 
beams  across  the  longitudinal  walls  and  connecting  them 
into  a  solid  platform  by  short,  brick  arches,  in  the  man- 
ner ordinarily  pursued  in  fire-proof  structures.  The* 
roadway  on  this  platform  must  follow  the  same  general 
arrangement  as  on  the  main  bridge.  The  horse  car  rails 
with  the  iron  tramways  alongside  for  wagon  wheels  will 
be  continued  through.  These  rails  and  irons  will  be 
secured  to  longitudinal  wooden  sleepers,  which  latter 
are  fastened  to  the  iron  beams  underneath.  Wood  is 
required  to  give  the  necessary  elasticity,  and  if  properly 
prepared  will  last  a  long  time.  The  central  space  in 
each  tramway,  where  the  horses  walk,  must  be  filled  with 
a  suitable  pavement,  probably  of  wooden  blocks,  which, 
in  such  a  place,  will  be  very  durable,  for  the  reason  that 
the  causes  which  usually  wear  out  wooden  pavements 
are  not  found  here,  as  it  is  well  drained  by  the  slope;  the 
frost  will  not  upheave  it,  and  since  it  will  not  have  to  be 
taken  up  for  any  purpose,  it  will  wear  evenly  all  over. 
The  space  between  the  tramways  can  be  filled  in  with 
asphalt  or  concrete. 

Under  the  principal  railway  tracks  where  the  passen- 
ger trains  run,  we  have  the  option  to  leave  the  spaces  be- 
tween open  or  closed.  If  left  open  they  will  furnish 
light  for  the  spaces  underneath,  which  otherwise  must 
come  from  the  distant  end  walls;  but,  on  the  other  hand, 


30 


a  separate  roof  would  be  required  underneath  to  carry 
off  the  rain ;  hence,  if  these  spaces  are  not  to  be  utilized 
at  once  it  may  be  as  well  to  close  them  ;  either  way  is 
immaterial,  as  far  as  the  track  is  concerned. 

The  trains  of  passenger  cars  will  be  from  400  to  500 
feet  in  length.  The  floor  of  such  a  car  from  two  and  a 
half  to  three  feet  above  the  track,  hence  the  platform 
on  which  the  passengers  stand,  must  be  at  the  same 
height  above  the  track  for  the  distance  already  given. 
This  will  take  in  a  greater  portion  of  the  Brooklyn  ap- 
proach, and  about  one-third  of  the  New  York  approach. 
It  will  therefore  be  advisable  to  continue  the  central 
sidewalk  at  this  elevation  over  the  remainder  of  the  New 
York  approach  until  it  passes  the  anchorages.  We  thus 
fivoid  two  awkward  sets  of  steps  up  and  down.  This 
height  of  three  feet  also  affords  an  opportunity  of  put- 
ting in  side  lights  along  the  central  platform,  and  thus 
lighting  the  place  underneath,  even  if  the  railroad  tracks 
are  closed  up  tight. 

As  to  the  material  of  which  this  platform  should  be 
made,  I  prefer  yellow  pine  planking  to  stone  flagging  ; 
planking  is  more  pleasant  to  walk  on,  does  not  get  slip- 
pery in  freezing  weather  like  stone,  which  is  quite  a  con- 
sideration on  account  of  the  grade ;  it  can  be  easily  re- 
paired piece  by  piece  without  interrupting  the  whole 
travel,  as  would  be  the  case  when  replacing  flagging.  At 
the  ends  of  the  approaches,  between  Chatham  and 
William  streets,  and  Sands  and  Prospect  streets,  the 
spaces  will  be  covered  with  regular  pavement. 

All  the  bridges  at  the  street  crossings  will  be  plate 
girders  except  the  Franklin  Square  bridge  and  the  cross- 
ings at  William  and  North  William  streets,  where  solid 
brick  arches  may  be  p'referable,  provided  we  have  the 
necessary  head  room  underneath. 

Between  North  William  and  Chatham  streets  there 
will  be  required  an  underground  room  for  holding  the 
return  wheels  of  the  propelling  ropes  and  the  sliding 
frames  for  tightening  the  latter. 


31 


A  brief  recapitulation  of  the  foregoing  remarks  goes 
to  show  that  all  the  questions  involved  in  this  approach 
are  pretty  well  settled  except  one  ;  which  is  the  manner 
of  supporting  the  roadway  of  the  approach.  Either  of 
the  two  methods  proposed  are  adequate  as  far  as  the 
mere  supporting  power  is  concerned.  The  plan  of 
wrought  ir<»n  columns  will  probably  be  a  little  cheaper 
as  regards  first  cost,  but  independent  of  price  the  plan 
of  brick  arches  and  piers  has  so  many  considerations  in 
its  favor  that  it  should,  on  the  whole,  be  adopted.  Brick 
piers  can  be  erected  with  equal  rapidity,  will  be  more 
substantial  and  permanent  in  their  character, and  abso- 
lutely resist  the  action  of  lire,  whilst  iron  columns  do 
not.  The  manner  in  which  the  division  and  surround- 
ing walls  will  be  tied  together  gives  also  a  greater 
stability  to  the  whole  structure,  besides  furnishing  one 
great  step  towards  future  utilization. 

Foundations  for  the  walls  of  the  approach  must  be  of 
various  characters,  according  to  the  nature  of  the  ground. 
In  the  "  Swamp"  piles  must  be  driven  ;  in  the  sand  we  can 
make  concrete  foundations;  and  in  more  compact  ground 
ordinary  rubble  walls  will  answer,  with  broad  flat  stones 
for  footings. 

The  foundation  walls  and  brick  arches  resting  against 
the  rear  of  the  anchorage  will  add  a  little  weight  thereon, 
which  is  not  undesirable. 

The  amount  of  work  required  to  perfect  the  drawings 
for  the  details  of  these  approaches  — involving,  as  it 
does,  designs  for  a  series  of  structures  a  quarter  of  a 
mile  long — is  very  great.  Fortunately  we  have  in  Mr. 
Hildenbrand  an  architect  both  by  profession  and  prac- 
tice. The  Grand  Central  Depot  was  built  from  draw- 
ings made  by  him.  and  his  designs  for  the  International 
Exhibition  building  show  great  capacit}7.  Since  his 
release  from  the  duties  of  stone  inspection,  Mr.  Vander- 
bosch  has  also  rendered  very  able  and  efficient  aid  in 
making  these  designs,  a  work  which  comes  in  the  line  of 
his  profession. 


32 


In  conclusion,  I  must  express  my  satisfaction  and  ap- 
preciation of  the  services  rendered  by  the  gentlemen 
who  have  assisted  me  thus  far  in  the  construction  of  the 
various  parts  of  this  work.  Owing  to  my  prolonged  ill- 
ness and  consequent  enforced  absence,  the  actual 
execution  of  the  work  lias  largely  devolved  upon  my 
assistants.  As  Engineer  in  charge.  Mr.  Martin  lias  had 
a  general  superintendence  of  the  whole  work,  which  he 
has  done  in  his  usual  faithful  and  energetic  manner. 

Col.  Paine,  in  addition  to  completing  the  New  York 
tower,  has  attended  to  all  the  details  connected  with  the 
work  and  tests  incident  to  the  wire  ropes  and  the  cable- 
wire,  a  task  for  which  he  has  shown  a  special  aptitude. 
He  has  given  to  this  subject  an  untiring  application, 
united  with  a  spirit  of  patient  investigation,  which  takes 
nothing  for  granted,  resulting  in  new  and  valuable  dis- 
coveries and  improvements. 

Mr.  Colling  wood  has  had  charge  of  the  New  York 
anchorage  for  the  past  two  years,  and  has  conducted 
this  work  to  a  successful  completion  in  thei  most  able 
and  efficient  manner,  and  in  a  remarkably  short  space  of 
time. 

Mr.  McNulty  successfully  completed  the  Brooklyn 
anchorage,  since  wliich  time  he  has  been  employed  in 
the  office  making  plans  and  designs  for  different  parts  of 
the  work. 

Mr.  Hildenbrand,  of  whose  ability  as  an  architect  I 
have  already  spoken  in  my  remarks  about  the  approaches, 
is  the  repository  of  most  of  the  calculations  and  plans 
pertaining  to  the  superstructure  of  the  Bridge. 

Mr.  Farrington,  of  whom  I  have  spoken  in  connection 
with  the  foot-bridge,  will,  after  its  completion,  continue 
in  immediate  charge  of  cable-making. 

All  of  the  more  important  specifications  for  materials 
issued  during  the  past  two  years,  together  with  the  re- 
ports upon  tests  of  steel  wire  recently  submitted  to  the 
Board  of  Trustees,  will  be  found  in  the  appendix  to  this 
report. 


So 


Below  is  given  the  revised  estimate  brought  np  to 
January,  1877,  showing  the  total  cost  of  the  work  and 
the  expenditure  yet  to  be  made  to  complete  it. 

Respectfully  yours, 

W.  A.  ROEBLING, 

Engineer. 


ESTIMATE  OF  JANUARY  1st,  1877. 


Amount  required  to  complete  the  Brooklyn  tower   87,000.00 

Amount  required  to  complete  the  New  York  tower   14,778.00 

Amount  required  to  coniplele  the  Brooklyn  anchorage.  50,948.41 

Amount  required  to  complete  the  New  York  anchorage.  59,552.41 

Suspended  superstructure,  original  $3, 011, 010. 00 

Expended  during  1876   94,056.42 

Suspended  superstructure,  amount  yet  to  be  expended  2.916,953.58 

Approaches   742,516.00 

Toll  Houses  and  gateways   20,000.00 

Engineering  (unexpended  balance)   108,886.76 

Contingencies  (unexpended  balance)   93,957.49 

Am't  required  to  complete  the  Bridge  and  approaches.  4.020,592.65 

Land  yet  to  be  taken  (unexpended  balance)   2,267,381.76 

Amount  yet  to  be  expended  for  land,  and  to  complete 

the  structure   6,287,974.41 


WHOLE  COST  OF  THE  BRIDGE  AS  NOW  ESTIMATED. 

Amount   thus   far  expended,  as  per 

Treasurer's  statement  $7,059,808.49 

Deduct  receipts  for  rents,  wharfage 

and  material  sold   164,896.41 


$6,894,912.08 

Add  liabilities  on  January  1,  1877   15,304.75 


Net  expenditure,  as  per  Treasr's  books.$6, 910,216.83 

Deduct  material,  etc.,  on  hand,  as  per 

inventories   82,064.92 

Total  net  expenditures  to  January  1,  1877   6.828,151.91 


Total  cost  by  present  estimate 

3 


$13,116,126.32 


APPENDIX. 


I. 

SPECIFICATIONS. 


SPECIFICATIONS  FOR    GRANITE    FACE-STONE    AND  ARCH- 
STONE,  REQUIRED  FOR  THE   NEW  YORK  TOWER, 
EAST  RIVER  BRIDGE,  APRIL,  1875. 

1.  Proposals  are  invited  up  to  April  loth,  1875,  for  the  delivery  of 
6,056  cubic  yards  of  cut  Face-stone,  Archstone  and  Dimension-backing, 
from  and  including  the  fourth  course  above  springing  line  of  arch  to  the 
coping,  comprising  a  height  of  68  feet. 

2.  An  inspection  of  the  plan  shows  three  solid  vertical  shafts  of  a  cru- 
ciform section,  extending  from  the  fourth  arch-course  to  the  upper  cornice, 
and  having  a  height  of  46  feet. 

3.  Above  this  is  the  upper  cornice,  extending  across  the  whole  width 
of  the  Tower,  having  a  total  height  of  about  22  feet,  and  comprising  two 
diamond  beads  with  a  necking  between  ;  an  outward  sloping  section  about 
9  feet  high,  a  square  cap  course,  and  the  coping  and  lower  roof-stone 
forming  the  roof  of  the  Tower. 

4.  The  three  vertical  shafts  are  connected  by  two  pointed  arches  which 
have  a  rise  of  35  feet  6  inches :  a  span  of  33  feet  9  inches,  and  a  width 
of  21  feet. 

5.  These  arches  consist  of  18  ring-stones  on  each  side,  surmounted  by 
a  key-stone. 

Above  the  arch  is  the  spandrel-tilling  of  varying  thickness  of  courses, 
and  covered  by  a  broad  band-course  at  the  line  of  the  key-stone.  The 
space  between  the  key-stone  and  the  cornice  is  occupied  by  a  recessed 
panel. 

(!.  The  interior  space  above  the  spandrel-filling  is  not  all  solid,  but  con- 
sists of  three  parallel  walls,  separated  by  two  hollow  spaces.  The  mid- 
dle wall  is  4  feet  2  inches  thick,  the  two  outer  ones  vary  from  4  feet 
2  inches  to  5  feet  3  inches  in  thickness,  and  the  width  of  the  hollow  spaces 
varies  from  4  feet  3  inches  to  4  feet  9  inches. 

7.  In  order  to  maintain  communication  with  the  roof  of  the  Tower,  a 
hole  is  built  into  the  masonry  on  the  south  side,  commencing  at  the  sec- 
ond arch-course,  extending  through  the  spandrel-filling  into  the  hollow 


33 


spaces  above  the  arch,  and  opening  out  upon  the  roof  through  a  trap- 
door. 

8.  A  detailed  plan  on  the  scale  of  five  feet  to  the  inch  will  be  furnished 
for  all  the  regular  courses,  as  well  as  for  the  Arch-stone  and  spandrels, 
giving  the  exact  dimension,  location,  and  denomination  of  each  stone, 
and  an  isometrical  projection  where  necessary. 

The  plan  of  bond  must  be  in  every  case  adhered  to. 
Templates  will  be  furnished  for  each  Arch-stone. 

9.  The  rises  will  vary  in  the  main  from  22  to  30  inches.  They  will  be 
fixed  on  the  plan  of  every  course. 

CHARACTER  OF  CUTTING  IN  THE  DIFFERENT  SECTIONS  OF  MASONRY. 

10.  The  Pace-stone  of  the  buttresses  in  the  vertical  sections  will  all 
be  rock-face,  with  a  draft  cut  all  around  the  lace  l£  inches  wide. 

The  appearance  of  the  stone  will  be  that  of  subdued  rock-face,  the  pro- 
jections not  to  exceed  3  inches. 

No  special  pains  need  be  taken  with  this  rock-face,  the  idea  simply 
being  to  have  it  less  bold  than  that  below  the  floor.  It  will  not  be  re- 
quired that  the  rock-face  shall  be  leveled  off  to  one  uniform  face 
3  inches  high,  but  merely  that  the  projection  shall  not  exceed  3  inches. 

11.  Since  the  draft-line  extends  around  the  four  edges  of  the  face  of 
every  stone,  it  follows  that  all  the  outer  as  well  as  the  inner  angles  of  the 
buttresses  will  have  a  clear  vertical  draft  of  l£  inches  wide. 

The  color  of  the  stone  is  immaterial,  but  it  must  be  granite,  of  good 
clear  stock. 

12.  The  outward  slope  of  the  upper  cornice  will  be  cut  precisely  like 
the  one  in  the  cornice  below  the  floor. 

Each  stone  has  a  draft-line  of  1^  inches  wide  all  around  the  face,  and 
the  face  itself  is  pointed  down  to  a  uniform  projection  of  about  \  an 
inch. 

The  color  of  the  corn;ce  stone  must  be  light,  so  as  to  form  a  contrast 
with  the  darker  buttress  stone. 

13.  Square  openings  are  left  in  the  sloping  part  of  the  upper  cornice  for 
the  passage  of  the  cables. 

ARCH-STONE. 

14.  The  number  and  dimensions  of  the  Arch-stones  are  given  in  the 
plans.  It  will  be  noticed  that  the  lower  Arch-stones  are  not  alike  on 
each  side,  owing  to  the  fact  that  the  arch  is  not  symmetrical  with  the 
centre  lines  of  outer  and  middle  buttresses.  It  will  also  be  observed  that 
the  extrados  and  intrados  do  not  form  concentric  curves,  but  that  the 
Arch-stones  become  smaller  as  they  approach  the  vertex. 

15.  The  face  of  the  outer  ring-stone  of  the  arch  will  be  cut  with  a  draft 
all  around  the  five  edges.  This  draft  will  be  three  inches  wide  along  the 
curved  edge  (intrados),  two  inches  wide  along  the  two  adjoining  edges 


39 


(lower  and  upper  bed),  two  inches  wide  along  the  upper  horizontal  bed, 
and  2  inches  wide  aloug  the  vertical  edge. 

The  face  within  the  draft  will  be  cut  down  to  a  uniform  projection  H 
inches  high.  This  inner  face  is  simply  rough-pointed  to  a  uniform  level, 
but  without  plug-holes. 

The  intrados,  or  inner  facing  of  the  Arch-stone,  will  be  pointed  down 
smooth,  or  else  rough-axed  or  peen-haramered.  The  cutting  need  not  be 
fine,  but  no  plug-holes  are  admissible. 

16.  It  will  be  noticed  that  the  Arch-stones  are  cut  on  all  faces. 

Patterns  will  be  furnished  of  full  size  for  each  Arch-stone  and  detail- 
drawings  given  on  a  large  scale,  with  the  exact  dimensions.  Iti  these 
patterns  as  well  as  in  the  detail-drawings,  allowance  is  already  made  for 
joints,  hence  the  stones  must  be  cut  exactly  to  the  patterns  or  given 
dimensions. 

The  upper  corner  of  each  ring-stone  is  a  right  angle ;  a  horizontal  bed 
is  thus  formed  for  the  spandrel  course  above  to  rest  on.  Moreover,  owing 
to  the  different  curvature  of  the  extrados  and  intrados,  the  radial  joints 
all  differ  in  length,  being  1  foot  deeper  at  the  springing  line  of  the  arch 
than  at  the  key-stone,  the  former  depth  being  5  feet  and  the  latter  4 
feet. 

The  courses  of  ring-stones  are  bonded  among  themselves,  the  alternate 
courses  containing  respectively  4  and  5  stones. 

17.  Reference  has  alreadv  been  made  to  the  hole  in  the  masonry  on  the 
south  side.  It  is  3  feet  by  2  feet  5  inches,  and  passes  up  vertically  and 
inclined,  coming  out  in  the  hollow  space  above  the  arch.  Its  course  is  ac- 
curately traced  in  all  the  plans,  and  care  must  be  taken  that  all  stones 
facing  it,  Face-stones  as  well  as  dimension-backing,  do  not  lack  in  width 
or  length,  and  are  nicely  sqnared-off. 

18.  The  key-stone  forms  a  pointed  wedge,  7  feet  6|  inches  high  and  5 
feet  £  inch  wide. 

It  projects  13  inches  beyond  the  face  of  the  arch,  and  care  must  there- 
fore be  taken  that  the  projecting  part  is  cut  as  fine  as  the  lace.  This 
latter  consists  of  two  raised  panels  each  2  inches  high,  separated  from 
the  outer  edges  of  the  stone  and  from  each  other  respectively  by  7-inch 
draft-lines  along  the  sides  and  9-inch  draft-lines  along  the  upper  edges. 
The  projecting  panels  are  sloped  on  the  upper  side  to  shed  water. 

The  whole  face  of  the  key-stone,  panels  and  drafts,  is  6-cnt  work.  There 
are  four  pieces  of  front  key-stone.  The  inner  key-stones,  six  in  number, 
are  cut  after  the  same  pattern,  but  only  5  feet  6^  inches  high,  and  uo  other 
work  put  on  them  than  good  pointed  beds  and  builds,  not  lacking  in  any 
dimension,  and  having  none  or  only  small  plug-holes. 

SPANDREL-COURSES. 

19.  In  place  of  projecting  the  ring-stone  beyond  the  face  of  the  span- 
drel-courses, as  is  usually  done,  the  reversed  plan  is  adopted. 

The  lowest  spandrel-course  will  project  £  inch,  each  succeeding  one  £ 


40 


inch  more,  so  that  the  upper  spandrel- course  below  the  key-stone  pro- 
jects 7£  inches  beyond  the  face  of  the  aroh. 

20.  The  top  spandrel,  or  band-course,  in  range  with  the  key-stone,  pro- 
jects, in  addition,  2%  inches  more,  making  10  inches  in  all  beyond  the 
face  of  the  arch. 

This  band-course  will  be  30  inches  high,  and  the  projecting  part  of  its 
top-bed  will  be  sloped  down  2  inches  to  form  a  water- shed. 

The  two  double  headers  in  the  middle  buttress  of  this  course  will  have 
the  figures  "  1875"  cut  on  their  faces.  In  order  to  make  these  prominent,  a 
raised  panel  3  inches  high,  25  inches  wide,  and  6  feet  9  inches  long,  with  a 
draft-line  2^  inches  wide  all  around,  will  be  cut  on  the  face.  What  re- 
mains of  the  stone  is  rock-face,  as  usual  with  H  inch  drafts  on  the  three 
sides.  From  this  raised  panel,  which  must  be  smooth  eight  or  ten  cut- 
work,  the  figures  project,  in  addition,  3  inches  more.  They  are  about  21 
inches  high  and  4  inches  broad,  and  their  exact  shape,  position  and  size, 
will  be  given  in  a  full-sized  drawing.  The  upper  face  of  these  figures 
must  be  highly  polished,  so  as  to  form  aMark  contrast  against  the  white 
back-ground  of  the  panel. 

21.  The  face  of  the  spandrel-courses  will  be  cut  without  drafts,  either 
horizontal  or  vertical,  and  will  be  pointed  down  to  a  uniform  surface,  a 
little  finer  than  the  pointed  work  of  the  sloping  offsets,  and  without  plug- 
holes on  the  face,  but  not  near  as  fine  as  6-cut  work. 

The  spandrels  should  convey  the  idea  of  one  stone  extending  from  the 
buttress  to  the  Arch-stone ;  hence  the  intermediate  vertical  joints  must 
be  worked  close  and  snug. 

22.  The  band-course  has  horizontal  drafts  3  inches  wide.  Xext  to  key- 
stone and  buttress,  it  has  vertical  drafts  9  inches  wide.  The  intermediate 
vertical  joints  have  no  drafts.  The  raised  panel  formed  by  the  drafts  is  2 
inches  high,  its  face  being  pointed  work.  Along  its  upper  edge  it  is 
sloped  to  shed  water.  Care  must  be  taken  that  this  panel  comes  clear 
out  to  the  intermediate  joints,  with  sharp  and  unbroken  edges. 

This  stone  must  be  of  a  light  color. 

23.  It  will  be  noticed  that  the  thickness  of  the  spandrels  decreases  as 
we  go  up. 

The  thickness  of  the  buttress-couroes  likewise  diminishes  to  the 
fifth  course  below  the  band-course.  From  here  on,  the  buttress-courses 
are  uniform,  whereas  the  spandrel-courses  are  notched  out  to  form  the 
bond. 

There  is,  consequently,  one  more  spandrel  than  buttress-course ;  it  is 
called  135£th  course. 

24.  The  courses  above  the  band-course,  six  in  number,  form  what  is 
called  the  recessei  panel,  because  they  step  10  inches  back  from  the  face 
of  the  band-course,  ranging  plumb  with  the  general  face  of  the  arch. 
Their  rises  are  the  same  as  the  adjacent  buttress-stone  with  which  they 
bond  in. 

Each  stone  will  have  a  horizontal  draft  of  1^  inches,  and  in  the  corners 


41 


next  to  the  buttresses  there  will  be  a  vertical  draft  9  inches  wide. 
Between  the  draft  is  subdued  rock-face,  projecting  not  more  than  2  inches. 
This  horizontal  draft  is  continuous  between  the  buttresses,  and  hence  the 
vertical  joints  have  no  draft. 

PARALLEL  WALLS. 

25.  Above  the  upper  line  of  the  key-stone  the  filling  above  the  arches 
is  no  longer  solid,  but  will  consist  of  three  parallel  walls,  inclosing  two 
parallel  hollow  spaces  of  the  sizes  given"  in  §  6. 

The  centre  wall  will  consist  of  a  single  stone  4  feet  2  inches  wide,  of  vary- 
ing length,  to  break  joint,  with  an  occasional  binder  reaching  across  the 
space  to  tie  the  walls  together.  At  a  point  4  feet  above  the  arch-filling 
there  is  a  hole  in  the  middle  wall  2  feet  by  4  feet  to  connect  the  hollow 
spaces.  The  stones  of  this  middle  wall  are  considered  as  dimension- 
backing,  but  where  they  face  the  hollow  epaces  rock-face  will  be  allowed. 
The  same  holds  true  for  the  rear  of  the  face-stones  which  face  the  hollow 
spaces. 

UPPER  CORNICE. 

2G.  This  consists  of  light  colored  stone  throughout.  The  lowest  section, 
which  comprises  two  diamond  beads  of  16£  inches  high  each,  with  a  smooth 
necking  or  band  of  29  inches  between.  It  extends  around  the  entire 
tower.  The  cutting  will  be  G-cut  work  like  the  coping,  without  draft  of 
any  kind,  except  the  sloping  portion  above  upper  bead,  which  will  have  a 
l£  inch  draft  around  it,  and  be  pointed  down  to  £  inch  projection,  and  the  . 
portion  below  the  lower  bead,  which  will  have  a  l£  inch  draft  around  it 
and  be  rock-face. 

27.  The  outward  slope  is  about  9  feet  high,  and  also  extends  around  the 
whole  Tower.  The  face  of  each  stone  has  a  draft  line  of  l£  inches  all 
around  the  four  edges:  and  the  panel  within  is  pointed  work  of  about  £ 
inch  uniform  projection.  Where  the  rear  face  of  these  stones  faces  the 
hollow  spaces  it  can  be  rock-face;  but  where  it  joints  dimension-backing 
it  must  be  cut  true  and  plumb  like  the  latter. 

28.  Openings  are  left  in  these  courses  in  the  buttresses  for  the  passage 
of  the  main  cables.  These  openings  are  square  on  the  external  face,  but 
enlarge  inwardly  towards  the  saddle-plates.  The  inner  faces  of  the  stone 
in  ihese  openings  will  be  cut  vertical,  and  must  be  rough-axed  or  rough- 
pointed,  but  without  plug-holes. 

29.  Above  the  slope  is  the  square  cap-course  projecting  1  foot,  and  ex- 
tending over  the  entire  Tower,  thereby  covering  the  hollow  spaces.  It 
is  24  inches  high,  consists  in  the  main  of  large  stones,  and  must  be  6-cut 
work. 

The  coping  and  lower  roof-stone  above  are  in  two  courses,  and  extend 
over  the  whole  space,  with  the  exception  of  the  saddles,  where  an  un- 
covered space  is  left.  The  face  of  the  cap  and  coping-stone  is  smooth  6- 
cut  work,  like  the  lower  coping  at  the  floor-line. 

The  projecting  sqir  re  cap  course  will  have  a  water-drip  cut  in  its  lower 


4^ 


bed  2  inches  from  the  outer  edge,  and  being  l£  inches  wide  by  1  inch 
deep. 

The  upper  roof-stones  are  cut  on  the  upper  surface  according  to  the 
various  slopes  and  lines  corresponding  to  the  lines  of  the  water-shed  and 
the  buttresses,  as  shown  on  the  plan.  The  cutting  will  be  smooth  6-cut 
work  like  the  face.    All  joints  must  be  cut  close  and  true. 

DIMENSION-BACKING. 

30.  All  dimension-backing  must  b3  cut  exactly  to  the  size  given  on  the 
plans,  as  allowance  for  joints  is  already  made  in  these  figures.  The 
beds  and  builds  must  be  of  the  usual  quality,  and  the  sides  must  be  cut 
square  and  true,  or,  if  not  square,  exactly  to  the  angle  given  on  the  plan. 
The  greatest  pressure  comes  under  the  saddle-plates ;  hence  special  care 
must  be  taken  that  all  dimension-backing  under  the  saddles  for  four 
courses  below — that  is,  from  151st  to  147th  course — are  perfectly 
sound,  without  crack  jor  flaw.  Those  directly  under  the  saddle-plates 
shall  have  no  plug-holes  whatever,  neither  in  lower  nor  upper 
bed.  Tnese  are  the  stones:  Nos.  49,  51,  52,  53,  54,  61,  62,  63, 
64,  65,  66,  67,  74,  75,  76,  77  and  78,  of  dimension-backing,  and  Nos. 
41,  44,  48,  32,  36,  20,  24  and  27,  of  face-stones  of  151st  course. 
The  outlines  of  the  saddle-plates  are  traced  on  the  plan  in  blue  lines,  so 
as  to  show  which  portion  of  the  face-stone  must  be  free  from  any  plug- 
hole. All  the  above-named  stones,  besides  Nos.  3,  8,  12  and  17  must  be 
cut  exact  to  dimension  and  be  square  and  true  in  order  to  make  close 
joints. 

REMARKS  ON  THE  CUTTING  OF  THE  STONE. 

31.  The  upper  and  lower  beds  of  all  face-stone  and  dimension-backing 
must  be  rough-axed  and  cut  true  and  parallel  to  each  other,  as  well  as 
square  to  the  face  where  the  work  is  plumb. 

The  bedding  must  be  sufficiently  true  and  ejven  for  j-inch  joints.  It 
must  bear  the  straight-edge  all  over,  but  need  not  be  fine.  Square  and 
parallel  cutting  of  beds  will  be  insisted  upon.  No  hollow  or  slack  cutting, 
or  falling  away  towards  the  rear  of  the  bed,  will  be  permitted. 

The  vertical  joints  of  each  stone  must  be  sufficiently  true  to  make  ^- 
inch  joints.  They  must  be  cut  square  with  the  face  of  the  stone  for  a 
distance  back  equal  to  the  width  of  the  bed  of  the  adjacent  stretcher. 
Beyond  that  the  side  and  rear  face3  may  be  left  rough,  in  case  they  ad- 
join common  backing.  But  where  they  join  dimension-backing  all  faces 
must  be  throughout  plumb  and  true. 

32.  In  regard  to  the  dimensions  of  the  stones  the  following  remarks 
shall  be  noticed : 

All  stones  shall  be  cut  full  to  the  rise  given  in  the  plan,  except  other- 
wise stated  thereon. 

Each  Face-stone  must  be  cut  \  inch  short  in  width  or  length  for  each 
'ace-joint  between  tnemselves,  but  must  have  full  width  and  length  when 
they  join  dimension-backing  or  other  Face-stone  inside  the  wall,  because 
in  the  latter  two  cases  allowance  is  already  made. 


43 


Arch-stone  and  dimension-backing  must  be  cut  exactly  to  the  patterns 
for  the  one  and  to  the  given  dimensions  for  the  other.  All  face  Arch- 
stone  will  be  cut  \  incli  short  in  width,  and  all  middle  Arch-stone  £  inch. 

The  given  figures  never  include  raised  panels  or  rock-face,  but  give 
only  the  distance  between  the  edges  of  the  drafts. 

To  illustrate  the  above  by  an  example,  some  stones  of  the  133d  course 
shall  be  nearer  described,  as  follows  : 

No.  1,  marked  3  feet  3  inches  by  7  feet  1  inch,  must  be  cut  3  feet  2f 
inches  by  7  feet  f  inches.  Xo.  2,  marked  4  feet  by  7  feet  1  inch,  must 
be  cut  3  feet  ll£  inches  by  7  feet  f  inches. 

No.  4,  marked  10  feet  6  inches  by  3  feet  6  inches,  to  be  cut  10  feet  6 
inches  by  3  feet  5£  inches. 

No.  5,  marked  9  feet  by  3  feet  6  inches,  to  be  cut  about  9  feet  by  not 
less  than  3  feet  6  inches,  with  a  face  of  5  feet  9  inches. 

No.  G,  marked  3  feet  3  inches  by  9  feet  4  inches,  to  be  cut  3  feet  2\ 
inches  by  9  feet  4  inches. 

No.  7.  Arch-stone,  marked  3  feet  9  inches  wide,  to  be  cut  3  feet  S| 
inches  without  the  panel  ;  together  with  the  panel  the  whole  width  will 
be  3  feet  10^  inches. 

No.  8,  Arch-stone,  marked  4  feet  8  inches  wide,  to  be  cut  4  feet  7£ 
inches  wide. 

No.  47,  marked  3  feet  3  inches  by  8  feet  5f  inches,  to  be  cut  3  feet  3 
inches  by  8  feet  5^  inches  exactly. 

No.  25,  marked  10  feet  by  3  feet  6  inches,  to  be  cut  10  feet  by  3  feet 
5|  inches. 

No.  79,  marked  3  feet  by  8  feet  5f  inches,  to  be  cut  these  figures  exactly. 

33.  In  every  case  the  best  bed  of  the  stone  must  be  the  bottom  bed. 
No  plug-holes  will  be  allowed  more  than  9  inches  in  diameter  and  1£ 

inches  deep,  and  must  not  occupy  more  than  one-fifth  the  area  of  the 
stone ;  they  must  not  tome  within  three  inches  of  the  cuter  edge.  But 
in  all  stones  directly  under  the  saddle-plates,  as  already  stated,  no  plug- 
holes can  be  permitted.  Unless  the  width  of  a  stretcher  is  indicated  in 
the  plans,  it  is  understood  to  be  no  less  than  one  and  one-half  times  the 
rise,  and  when  the  face  and  back  are  not  parallel  the  average  width  must 
be  no  less  than  one  and  one-half  times  the  rise. 

The  length  of  headers,  if  not  stated  on  the  plan,  must  be  no  less  than 
three  times  the  rise.  Where  there  is  dimension-backing,  the  width  of 
the  header  must  be  uniform  throughout,  and  the  rear  face  cut  square. 

34.  No  common  backing  will  be  wanted.  All  Face-stones  with  a  sharp 
arris  must  be  boxed. 

All  stones  must  be  properly  lewised  with  a  flat  lewis,  and  a  portion  of 
the  Arch-stone  must  have  two  lewis  holes. 

GENERAL  REMARKS. 

35.  Steam-power  and  derricks  for  unloadmg  vessels  will  be  furnished 
by  the  Bridge  Company. 

The  crews  of  the  vessels  must  assist  in  the  unloading ;  they  must 


44 


bring  the  stone  under  the  arm  of  the  derrick,  and  must  attach  the  lewis 
to  the  hoisting-block,  and  furnish  all  the  labor  that  is  required  on  board 
the  vessels. 

36.  The  delivery  to  commence  June  1,  1875,  and  the  stones  must  be 
all  delivered  by  Dec.  1st.,  1875. 

37.  In  case  mistakes  are  made  in  the  cutting  of  the  stone,  either  in  regard 
to  their  dimensions  or  in  the  character  of  their  faces,  beds  and  joints, 
different  from  the  drawings  and  specifications,  the  contractor  is  hereby 
distinctly  notified  that  such  stone  will  be  condemned,  and  must  be  re- 
placed by  a  new  one  if  there  is  time  to  send  for  it ;  and,  if  not,  then  the 
cutting  of  a  new  one  will  be  done  by  the  Bridge  Company  at  the  contrac- 
tor's expense ;  and  such  cost  of  labor  and  detention  will  be  deducted 
from  the  monthly  estimate. 

38.  Monthly  estimates  will  be  made  on  or  about  the  10th  day  of  each 
month  for  stone  delivered  during  the  previous  mouth,  deducting  15  per 
cent.,  which  sum  will  be  kept  as  a  guarantee  for  the  satisfactory  per- 
formance of  the  contract,  and  will  be  paid  in  one  month  from  the  time 
the  contract  is  complete,  and  it  is  understood  that  in  all  estimates  the  ex- 
act cubic  contents  of  the  stone  when  delivered  will  be  taken  and  no  more. 
In  no  case  will  the  rock-face  which  projects  beyond  the  draft-line  be 
measured  or  paid  for. 

39.  The  Bridge  Company  reserves  the  right  to  reject  any  or  all  bids 
offered  ;  and,  in  order  to  obviate  the  contingency  of  an  excessive  price, 
they  further  reserve  the  right  to  let  the  contract  in  two  or  more  parts,  if 
it  should  prove  to  their  advantage  so  to  do. 

40.  Proposals  will  be  directed  to  the  New  York  Bridge  Company,  21 
Water  street,  Brooklyn. 

W.  A.  ROEBLING, 

Chief  Engineer  New  York  Bridge  Company. 

QUANTITIES  OF  MASONRY. 
[Note. — Stone  having  about  the  same  quality  of  cutting  are  grouped 
■  together  in  brackets.] 


Buttress  Face-stone,  draft-line  ' 

Panel  above  arch  

Outer  slope  of  upper  cornice  

Spandrel-filling  

Band  course  

Necking  and  square  course  

2  bead  courses  and  low'r  roof-course 

Upper  Roof-stone  or  coping. „  

Arch-face  stone  

Inner  Arch-stone  and  in'r  Keystone 

4  Keystones  

Stones  with  figures  il  1875  "  

Dimension  backing  

Total   


Cubic  Yds 


1483 
331 
566 
270 

70 
317 
467 
370 
236 
345 

20 

Two  pieces. 
1 156 
6056 


Price 
per  Yard. 


Total. 


Per  piece 


45 


SPECIFICATIONS  FOR  GRANITE  CUT  STONE,  REQUIRED  FOR 
THE  PARAPETS  AT  THE  ROADWAY,  BROOKLYN  AND 
NEW  YORK  TOWERS,  EAST  RIVER  BRIDGE. 

1.  Proposals  are  invited  up  to  November  6,  1876,  for  the  delivery  of 
about  116  cubic  yards  of  Granite  Cut  Stone  for  parapets  on  top  of  the 
cornice  at  the  floor-line  of  the  bridge  towers. 

2.  The  parapet  has  a  height  of  5  feet  4  inches,  and  an  aggregate  length 
of  446  feet,  consisting  of  164  single  pieces,  which  vary  in  length  from  5 
feet  to  11  feet,  and  in  weight  from  f  to  1\  tons. 

3.  The  height  is  divided  into  three  courses,  called  the  base,  the  shaft 
and  the  cap. 

The  base  consists  of  a  stone  13  inches  high  and  18  inches  wide,  which 
is  surmounted  by  a  water-table  4  inches  high,  and  a  sloping  back  '2| 
inches.  The  vertical  shaft  has  a  height  ef  2  feet  11  inches,  and  a  width 
of  15£  inches.  In  order  to  relieve  the  uniformity  of  this  plain  surface, 
rectangular  panels  are  cut  in,  5  inches  deep.  The  height  is  1  foot  7 
inches,  and  their  sides  slope  towards  the  rear,  making  the  inner  face  only 
1  foot  4  inches  high.  The  different  lengths  of  the  panels  will  be  given  in 
the  detail  drawings. 

The  cap  consists  of  a  concave  quarter  oval  3f  inches  high,  a  square  belt 
6^  inches  high,  and  a  water-shed  2  inches  high,  making  a  total  height  or 
thickness  of  12  inches.  At  the  belt  or  greatest  projection  it  has  a  width 
of  20|  inches,  while  the  bottom  bed  is  only  17  and  the  top  face  15^  inches 
wide ;  the  latter  dimension  making  it  apparent  that  the  water-shed  must 
fall  back  5£  inches.  The  top  face  is  not  horizontal  or  parallel  to  the  bot- 
tom bed,  but  slopes  towards  the  rear  \  inch,  making  the  total  height  of 
the  cap  at  the  back  face  only  11£  inches. 

4.  In  order  to  drain  the  water,  trapezoidal  openings  will  be  cut  in  the 
base  at  suitable  places,  fixed  on  the  detail  drawings.  They  are  2 
inches  high,  2  feet  2  inches  long  in  front,  and  1  foot  8  inches  long  in  the 
rear. 

5.  As  each  stone  will  be  held  in  place  by  dowels,  the  contractor  is  re- 
quired to  drill  4  holes  in  each  stone  belonging  to  the  base  and  shaft;  two 
in  the  bottom,  and  two  or  occasioually  three  in  the  top-bed.  The  cap- 
stones will  require  only  two  holes  in  the  bottom  bed.  All  holes  in  the 
base-stones  and  those  in  the  bottom  of  the  shaft-stones,  must  have  a 
diameter  of  1 1  inches.  Those  in  the  cap-stones  and  in  the  top-bed  of 
shaft  will  be  only  1  finches.  The  depth  of  the  latter  shall  be  5  inches;  of 
those  in  the  bottom  of  base  9  inches,  and  of  those  in  the  top  of  base  and 
bottom  of  shaft  8  inches. 

It  will  be  strictly  required  that  all  of  these  holes  shall  be  drilled  per- 
fectly plumb. 

6.  Detail  plans  made  to  the  scale  of  2  inches  to  the  foot  will  be  fur- 
nished to  the  contractor,  which  will  guide  him  in  everything  not  described 
in  this  specification. 


46 


CHARACTER  OF  MATERIAL  AND  CUTTING. 

7.  The  material  used  must  be  granite  of  clear  stock,  fine  grain  and  light 
color,  such  as  Mount  Waldo,  Blue  Hill  or  Mount  Desert  Granite,  or  from 
East  Boston  quarry,  on  Fox  Island. 

No  sap,  or  stones  with  knots,  seams,  flaws  or  iron  will  be  admitted. 

8.  The  cutting  of  all  front  faces,  beds  and  side  joints  must  be  6-cut 
work  of  best  workmanship.  The  rear  face  can  be  pean-hammered  work, 
bvt  without  any  plug  or  drill-holes.  All  of  the  other  faces  must  also  be 
entirely  free  from  plug-holes.  All  sides  of  the  drain-holes  in  the  base  of 
the  panels  in  the  shaft,  and  of  the  concave  rounding  in  the  cap  must 
also  be  best  6-cut  work. 

9.  In  the  projecting  part  of  the  bottom  of  the  cap,  a  water  drip  must 
be  cut,  commencing  1  inch  from  the  edge,  being  triangular  in  shape,  £ 
inch  wide  by  £  inch  deep,  and  runuing  all  around  the  parapet. 

10.  The  dimensions,  as  given  in  the  detail  plans,  must  be  strictly  ad- 
hered to,  and  no  variation  from  them  whatever  will  be  allowed,  as  the 
harmony  of  the  whole  depends  on  them. 

11.  Stones  with  inaccurate  cutting,  for  instance,  faces  out  of  plumb  or 
beds  out  of  level,  or  insufficient  workiug  in  the  upper  moulding,  will  be 
rejected.    Also,  stones  with  broken  edges,  or  corners  in  any  part  of  the  face. 

12.  No  lewis-holes  will  be  allowed  in  the  cap-stones. 

13.  All  stones  must  be  properly  boxed  and  the  edges  protected. 

GENERAL  REMARKS. 

14.  Steam  power  and  derricks  for  unloading  vessels  will  be  furnished 
by  the  Trustees  of  the  Bridge.  The  crews  of  the  vessels  must  assist  in  un- 
loading ;  they  must  bring  the  stone  under  the  boom  of  the  derrick,  and 
attacli  the  chain  to  both  stone  and  hoisting  block ;  in  short,  do  all  the 
labor  that  is  required  on  board  the  vessels. 

15.  All  stones  must  be  delivered  at  the  stone-yard  of  the  New  York 
and  Brooklyn  Bridge,  at  the  Brooklyn  tower,  on  or  before  April  1st,  1877. 

16.  Incase  mistakes  are  made  by  the  contractor  in  cutting  the  stone, 
or  in  case  poor  material  or  workmanship  is  furnished,  contrary  to  this 
specification,  such  stone  will  be  condemned  and  must  be  replaced  by 
others  at  the  expense  of  the  contractor. 

17.  Payment  will  be  made  on  the  10th  of  every  month  for  all  stone 
delivered  during  the  previous  month,  15  per  cent,  being  deducted  until 
the  satisfactory  fulfillment  of  the  contract,  when  the  contractor  will  be 
paid  in  full.  Each  shipment  should  comprise  either  the  whole  or  the  half 
of  the  parapet  for  one  tower.  The  stone  for  the  Brooklyn  tower  must  be 
delivered  first,  and  no  stone  for  the  New  York  tower  will  be  paid  for 
before  all  of  the  Brooklyn  parapet  has  been  delivered. 

18.  Bids  may  be  made  per  lineal  foot  or  per  cubic  yard.  In  the  latter 
case  it  is  understood,  that  only  the  exact  contents  of  the  stone  will  be 
paid  for,  from  which,  however,  the  sunken  panels,  the  drain-holes  and 
dowel-holes  shall  not  be  deducted. 


47 


19.  The  Trustees  of  the  Bridge  reserve  the  right  to  reject  any  or  all 
bids  offered. 

20.  Proposals  must  be  directed  to  ';  The  Trustees  of  the  New  York  and 
Brooklyu  Bridge,"  21  Water  street,  Brooklyn. 

W.  A.  ROEBLING, 

Chief  Engineer  Ntw  York  and  Brooklyn  Bridge. 


SPECIFICATIONS  FOR  CUT  FACESTONE  AND  BACKING, 
LIMESTONE  AND  GRANITE  REQUIRED  FOR  THE 
NEW  YORK  ANCHORAGE,  EAST  RIVER 
BRIDGE,  1875. 

1.  Proposals  will  be  received  until  12  M.,  April  17th,  1875,  for  the 
delivery  of  5,008  cubic  yards  Cut  Face-stone  and  Archstone,  all  of  Lime- 
stone; 5,987  yards  Cut  Backing,  of  Limestone  or  Granite ;  and  for  294 
yards  Cut  Face-fctone,  and  644  yards  Dimension-backing,  of  Granite. 

2.  This  quantity  is  comprised  in  twenty-nve.  courses  of  Masonry,  as 
follows : 


0/ 


er  . 
c  to 

v.  3 


5  g 


4... 

4. . 

22in.. 

.  529  yds... 

yds...   98  vds. 

yds. 

..  627  yds. 

5... 

A... 

26  ".. 

30 

...  146    "  .. 

..  176  " 

6... 

B.„ 

28 

209 

"  ...  195    "  .. 

..  404  " 

7... 

C... 

30  ".. 

7  "  ... 

161 

"  ...  205    "  .. 

..  373  " 

8... 

D... 

26  ".. 

227 

..  227  " 

9.  . 

K... 

24  ".. 

.    21   44  ... 

229 

ii           _  <( 

..  250  " 

10... 

F... 

28  •«.. 

.  119  "  ... 

264 

..  383  " 

11... 

G... 

30  ".. 

.  391   "  .. 

256 

.  20 

yds. 

..  667  u 

12... 

11... 

26  ' 

228 

.  16 

..  244  " 

13... 

1... 

24 

300  "  ... 

208 

II  u 

.  16 

ti 

..  524  " 

14... 

K... 

22  ".. 

.  270  41  ... 

118 

.  14 

..  402  11 

15... 

L... 

26 

227 

II    (( 

.  17 

..  244  " 

16... 

M ... 

28  ".. 

'.  334  "  ... 

245 

.  17 

..  596  " 

17... 

N... 

30  ".. 

.  354  "  ... 

261 

II    II 

.  18 

.    633  " 

18... 

O... 

28  ".. 

.  316  "  ... 

■l  1  1 

.  17 

u 

..  577  " 

19... 

P... 

26  ".. 

.  319   "  ... 

188 

.  17 

ii 

..  524  " 

2('... 

Q.  • 

26  ".. 

.  348  "  ... 

182 

.  16 

ii 

..  546  " 

21... 

B... 

22  ".. 

.  298  "  ... 

152 

II   II 

.  14 

ti 

..  464  " 

22... 

S... 

30  ".. 

.  386  "  ... 

215 

.  18 

.i 

..  619  " 

23... 

T... 

26  ".. 

.  386  "  ... 

191 

.  16 

ii 

..  593  14 

24... 

U... 

24  ".. 

.  340  11  ... 

192 

.  15 

..  547  44 

25... 

V... 

24 

.  205  "  ... 

191 

.  15 

ii 

..  411  44 

26... 

w... 

26 

.  361    '  ... 

207 

.  16 

..  584  44 

27... 

X... 

28  ".. 

.  379  "  ... 

226 

.  17 

..  622  44 

28... 

Y... 

24  ".. 

.  324   "  .. 

190 

.  15 

..  529  '4 

Arch-Stone. — 

127  Sheeting  \  u 
40  Face   J 

..  167  44 

Totals. 


48 


RECAPITULATION. 


Limestone  Facing,  proper  4,841  yards. 

"        Arch  end  Facing   40  " 

"       Archstone  aside  from  end  fencing... .    127  " 


Total  Limestone  Face-stone  

Total  Limestone  or  Granite  Backing 


5,003  yards. 
5,987 


Granite  Dimension-backing, 


644  yards. 


Granite  Corners  

Total  Granite, 


294 


938  yards. 


Total  stone  to  be  furnished, 


11,933  yards. 


3.  Detail  drawings  on  a  scale  of  5  feet  to  the  inch  will  be  furnished  for 
every  course.  All  of  the  Grauite,  and  part  of  the  Limestone,  are  dimen- 
sion stone,  and  every  such  stone  will  be  designated  by  a  special  num- 
ber. Every  dimension  stone  must  be  cut  full,  and  no  allowances  made 
for  joints,  as  this  has  already  been  done.  The  bottom  bed  is  the  one  re^ 
ferred  to  in  every  case,  and  allowances  for  projections,  or  batter,  must  be- 
made  accordingly. 

Stones  having  no  special  number,  may  vary  in  dimensions  from  those 
given  on  the  plans;  provided  that  the  total  lengths  of  wall  faces  are  made 
up,  and  that  the  dimensions,  as  furnished,  do  not  make  it  necessary  to 
change  the  bond.  With  these  restrictions,  stretchers  may  range  from  5 
feet  to  10  feet  in  length,  and  shall  not  be  less  than  2  feet  9  inches  wide ; 
and  headers  may  range  from  5  feet  to  7£  feet  in  length,  and  shall  not  be 
less  than  3  feet,  or  more  than  3^  feet  in  width. 


4.  The  Limestone  shall  be  equal  in  quality  to  the  Kingston  Limestone, 
or  the  Lake  Champlain  Bluestone.  All  stone  with  dry  or  flinty  seams, 
which  split  with  frost,  will  be  rejected. 

5.  Of  this,  all  the  Face-stone  must  be  cut  with  a  bold  rock  face.  A 
small  portion  will  have  plumb  faces,  but  the  greater  part  must  be  cut  with 
a  batter  of  one-half  inch  to  the  foot  rise ;  this  will  be  indicated  by  a 
note  on  the  plan  in  every  case.  The  front  edges  will  be  pitched  off  to 
a  line.  No  draft  will  be  required  except  at  the  projecting  angle  of  corner 
stones,  on  which  there  shall  be  a  1|-  inch  vertical  draft  on  each  face. 

6.  The  upper  and  lower  beds  of  each  Face-stone,  must  be  rough-axed, 
and  cut  true  and  parallel  to  each  other;  and  where  the  work  is  plumb 
they  are  to  be  cut  square  to  the  face. 

The  stone  must  gauge  full  to  the  rise  The  bedding  must  be  suffi- 
ciently true  for  Half-inch  joints.  It  must  bear  the  straight-edge  all  over 
but  the  cutting  need  not  be  fine.  Square  and  parallel  cutting  of  the  beds} 
will  be  insisted  upon.  No  hollow  or  slack  cutting,  or  falling  away  to- 
wards the  rear  of  the  bed  will  be  permitted.    No  plug-holes  will  be 


LIMESTONE  MASONRY. 


49 


allowed  more  than  9  inches  in  diameter,  or  more  than  l£  inches  deep,  nor 
within  one  foot  of  each  other,  or  of  the  edge  of  the  stone. 

7.  The  vertical  joints  of  the  stone  must  be  eut  sufficiently  true  to  make 
half-inch  joints.  They  must  be  eut  square  with  the  face,  for  a  distance 
back  of  no  less  than  two  feet;  and  in  a  header  the  joints  must  be  cut 
back  full  and  square  for  the  whole  width  of  the  adjoining  stretcher.  They 
must  in  all  cases  be  perfectly  plumb,  and  at  right  angles  to  the  plane  of 
the  bed. 

8.  The  rear  faces  of  stretchers  may  be  left  rough  as  they  are  split 
from  the  quarry.  It  will  not  be  insisted  upon  that  they  shall  be  parallel 
to  the  front  faces,  although  it  is  preferred.  Headers  must  run  back  full 
width  for  at  least  half  their  length ;  the  tail  may,  however,  be  wider  than 
the  front,  and  their  rear  faces  may  be  left  as  they  come  from  the  quarry. 

9.  The  best  bed  of  every  description  of  stone  must  be  the  bottom  bed, 
and  the  lewis-holes  must  be  put  in  the  top  bed  and  not  the  bottom. 

10.  In  each  course  there  will  be  a  tail  bond  at  each  re  entrant  angle  of 
the  masonry.  "When  these  stones  are  headers  they  must  be  long  enough 
to  make  a  good  bond.  In  all  cases  they  must  be  properly  jointed  back, 
and  exposed  portions  of  their  faces  left  rock-face  as  on  other  Face-stone. 

1 1.  Courses  A  to  F.  inclusive,  will  have  ten  corner-stones  in  each,  with 
a  batter  on  two  faces.  Courses  E  and  F  will  also  have  four  corner-stones 
in  each,  with  a  batter  on  one  face  and  the  other  face  plumb;  and  four 
also  with  both  faces  plumb. 

12.  There  are  two  semi-circular  arches  running  through  the  rear  por- 
tion of  the  masonry,  having  a  length  at  the  springing  line  of  33  feet  6£ 
inches,  and  a  radius  of  intrados  of  7  feet.  They  will  have  an  average 
thiekuess  of  2  feet  6  inches,  and  be  laid  up  in  13  longitudinal  courses. 

The  upper  faces  of  these,  or  the  extrados,  may  be  left  as  they  come 
from  the  quarry,  with  the  exception  of  the  ring-stones,  at  the  two  ends, 
which  must  be  pointed  off  to  allow  of  a  half-inch  joint.  The  ends  and 
sides  of  each  archstone  must  likewise  be  pointed  to  allow  of  half-inch 
joints. 

The  outer  faces  of  the  end  archstones,  and  the  faces  of  all  forming  the 
intrados,  shall  be  rock-face,  with  a  draft  line  l£  inches  wide  cut  entirely 
around  each. 

BACKING. 

13.  The  backing  may  be  either  Limestone  or  Granite,  and  must  be  (mar- 
ried in  rectangular  blocks,  with  even,  parallel  beds.  Both  beds  will  be 
dressed  and  rough-axed,  so  as  to  make  joints  of  not  more  than  half  an 
inch.  All  four  vertical  sides  must  be  good  quarry  splits,  with  no  projec- 
tion exceeding  four  inches.  The  sizes  of  blocks  may  vary  from  twenty  to 
eighty  cubic  feet,  the  larger  blocks  being  preferred. 

The  stone  must  be  of  good  quality,  sound  aud  durable,  free  from  all 
cracks  and  seams  in  any  direction. 

No  plug-holes  more  than  nine  inches  diameter,  or  more  than  one  and  a 
half  inches  deep,  will  be  allowed  ;  and  at  least  three-fourths  of  the  upper 

4 


50 


bed  and  the  whole  of  the  lower  bed,  must  present  a  good,  uniform  bear- 
ing surface. 

GRANITE  MASONRY. 

14.  The  Granite  for  the  corners  must  be  white— as  white  as  the  Con- 
cord or  Hallowel  Granite,  or  that  from  East  Boston  quarry,  on  Fox  Is- 
land. It  must  be  uniform  in  color,  sound  and  durable,  free  from  all 
cracks  or  weak  spots,  and  without  seams  of  any  kind. 

15.  Every  course  above  F  has  ten  Granite  corners.  Each  face  of  these 
has  a  four-inch  projection,  which  is  made  by  cutting  a  chamfer  entirely 
around  the  face,  except  at  a  projecting  corner,  which  is  left  square.  The 
chamfers  must  be  fine  cut.  The  surface  between  the  chamfers  must  be 
pointed  to  a  uniform  surface,  and  a  1^  inch  chisel  draft  cut  entirely 
around  each  face.    Samples  of  the  work  can  be  seen  at  the  anchorage. 

The  cutting  of  beds  and  joints  shall  be  similar  to  that  of  other  Face- 
stones,  as  described  in  sections  5,  6  and  8. 

16.  The  Dimension-backing  must  be  sound  in  every  respect.  The  beds 
must  be  cut  as  described  in  sections  5,  6-  and  8;  and  the  sides,  except  at 
the  points  where  rock-face  is  noted  on  the  plans,  must  be  cut  square, 
vertical  and  true. 

As  these  stones  serve  to  distribute  the  pressure  from  the  Anchor-plates, 
it  is  very  important  that  care  be  taken  in  selecting  and  cutting  them. 
Fine  cutting  is  not  required. 

GENERAL  PROVISIONS. 

17.  All  stone,  both  face  and  backing,  must  have  suitable  lewis-holes. 
A  sample  lewis  will  be  furnished  to  the  contractor,  and  all  holes  must  be 
cut  so  that  it  will  tit  properly,  and  allow  the  lewis  to  be  inserted  its  full 
depth.  Xo  round  lewis-holes  will  be  permitted.  All  lewis-holes  must 
be  so  placed  that  when  the  stones  are  suspended  they  will  hang  in  proper 
position  for  setting. 

L8.  The:  stones  are- to  be  delivered  at  the  wharves  of  the  Bridge  Com- 
pany at  Red  Hook. 

Steam  power,  for  unloading  vessels,  will  be  furnished  by  the  Bridge 
Company,,  six  unloading  derricks  being  provided  at  the  ed^e  of  the  wharf. 
The  crews  of  the  vessels  must  assist  in  unloading.  They  must  bring  the 
stone  under  the  boom  of  the  derrick,  and  must  attach  the  hoisting  block 
to  the  lewis,  and  furnish  all  labor  that  is  required  on  board  the  vessel  for 
unloading  as  rapidly  as  the  Bridge  Company  may  require. 

19.  The  first  course  of  stone  must  be  delivered  by  July  1st,  and  the 
balance  at  the  rate  of  two  courses  per  week,  in  the  order  of  the  numbers. 
As  it  is  of  the  utmost  importance  that  the  delivery  of  the  stone  be 
prompt  and  in  the  order  of  the  courses,  this  rate  of  delivery  will  be  in- 
sisted upon and  if  there  are  delays  in  the  delivery,  from  any  cause 
whatever,  the  stone  will  be  obtained  elsewhere,  aud  the  attendant  ex- 
pense will  be  charged  to  the  contractor,  together  with  all  damages 
arising  from,  delays^ 


51 


20.  Parties  proposing  must  be  known  as  men  both  skilled  in  the  quar- 
rying and  cutting  of  stone,  as  well  as  prompl  and  reliable  in  their  business 
transactions,  and  must  bring  satisfactory  references  to  that  effect,  as  well 
as  to  their  financial  responsibility. 

21.  In  case  any  mistakes  are  made  in  the  cutting  of  the  stone,  as  re* 
gards  the  character  of  the  beds  or  joints,  or  in  the  rise,  or  if  there  are 
other  gross  violations  of  the  provisions  of  these  specifications,  the  con- 
tractor is  distinctly  notified  that  such  stone  will  be  either  wholly  con- 
demned and  thrown  back  on  his  hands,  or  else  a  proportionate  reduction 
in  the  price  will  be  made,  the  same  being  at  the  option  of  the  Engineer. 
Condemned  Facestone  will  be  reckoned  as  backing. 

22.  Any  question  as  to  the  intent  or  meaning  of  these  specifications 
shall  be  referred  to  the  Engineer,  whose  decision  shall  be  tinaL 

23.  The  Bridge  Company  reserve  to  themselves  the  right  to  reject  any 
or  all  bids  offered,  and  to  make  awards  of  separate  portions  of  the  total 
quantities  required,  if  to  their  interest  so  to  do. 

24.  Bids  will  be  received  as  follows: 

LIMESTONE. 

For  4,841  cubic  yards  Face-stone,  delivered,  per  cubic  yard  $. . . . 

For  127  u  Arch  Sheeting,  delivered,  per  cubic  yard. ...  $. . . . 
For      40        "         Arch  Face-stone  "  "   $.... 

LIMESTONE  OR  GRANITE. 
For  5,987  cubic  yards  cut  Backing  delivered,  per  cubic  yard  $. . . . 

GRANITE. 

For  644  cubic  yards  Dimension-backing,  delivered,  per  cubic  yard. .  $. . . . 
For  294         "        Granite  corners  a  11         ..  $  

25.  Monthly  estimates  will  be  made  on  or  about  the  10th  day  of  each 
month  for  stone  delivered  durincr  the  previous  month,  provided  that  no 
stone  will  be  estimated  for  until  all  courses  below  them  are  completed. 
Payments  will  be  made  on  these  estimates  after  deducting  15  per  cent., 
said  deduction  to  be  kept  as  a  guarantee  for  the  satisfactory  perform- 
ance of  the  contract,  and  to  be  paid  in  one  month  from  the  time  the  con- 
tract is  completed.  In  making  these  estimates  the  cubic  contents  of  the 
stone  will  be  taken,  except  that  the  rock-face  projections  will  not  be 
allowed  for. 

26.  Proposals  will  be  addressed  to  the  New  York  Bridge  Company, 
Brooklyn,  N.  Y.,  indorsed,  M  Proposals  for  Anchorage  Stone." 

W.  A.  ROEBLING, 

Engineer. 


52 


SPECIFICATIONS  FOR  CUT  FACE-STONE,  BACKING  AND  ARCH- 
STONE  OF  LIMESTONE   REQUIRED  FOR  THE  NEW 
YORK  ANCHORAGE,  EAST  RIVER  BRIDGE,  18*75. 

1.  Proposals  will  be  received  until  12  M  .  October  9,  1875,  for  the  de- 
livery of  1,000  yards  Cut  Backing;  899  yards  Cut  Face-stone;  and  731 
yards  Arch  Sheeting,  all  of  Limestone. 

2.  The  quantity  is  comprised  in  nine  courses  of  masonry,  as  follows: 
No.  of  Stones  to  be  Kise  of 

Course.    Marked.      Course.  Backing.  Facing.  Total. 

29   Z    28  in   250  yds  216  yds  466  yds 

30   A  ..  J    24  "  250    "     .....  140    "      I   ..402  « 

\    12  "   —  ....    12    "  ( 

31    B   28  "   —   120    "   120  " 

32   C   24  "    250    "    106    "   356  " 


1 

I 

J-..121 
I 

J 


39 


293 

60 
.  42 


Totals  1,000  yds.         899  yds.        1,899  yds 


RECAPITULATION. 

Limestone  Backing  

"  Facing  

"       Arch  Sheeting 

Total  

3.  Detail  drawings  on  a  scale  of  five  feet  to  the  inch  will  be  furnished 
for  every  course,  and  templates  and  drawings  for  the  archstone.  A  part 
of  the  stone  are  dimension  stone,  and  each  will  be  designated  by  a 
special  number.  Every  dimension  stone  must  be  cut  full,  and  no  allow- 
ances made  for  joints  or  beds,  as  this  has  been  already  done. 

The  bottom  bed  is  the  one  referred  to  in  every  case,  and  allowances  for 
projections  or  batter,  must  be  made  accordingly. 


1,000  cubic  yds. 
899  " 
731  " 

2,630  cubic  yds. 


53 


4.  Stones  having  no  special  number  may  vary  in  dimensions  from  those 
given  on  the  plans,  provided  that  the  total  lengths  of  wall  faces  are  made 
up.  and  that  the  dimensions,  as  furnished,  do  not  make  it  necessary  to 
change  the  bond.  "With  these  restrictions,  stretchers  may  range  from  5  to 
10  feet  in  length,  and  shall  not  be  less  than  2  feet  9  inches  wide;  and 
headers  may  range  from  5  to  6  feet  in  length,  and  shall  not  be  less  than 
3  feet,  or  more  than  3^  feet  in  width. 

5.  The  limestone  shall  be  equal  in  quality  to  the  Kingston  limestone, 
or  Lake  Champlain  blnestone.  All  stone  with  dry  or  flinty  seams 
which  split  with  frost,  will  be  rejected. 

6.  The  face-stone  mnst  be  cut  with  a  bold  rock-face.  A  small  portion 
will  have  plumb  faces,  but  the  greater  part  must  be  cut  with  a  batter  of 
one-half  inch  to  the  foot  rise ;  this  will  be  indicated  by  a  note  on  the 
plan  in  every  case.  The  front  edges  will  be  pitched  off  to  a  line.  No 
draft  will  be  required  except  at  the  projecting  angle  of  corner  stones,  on 
which  there  shall  bean  l£  inch  draft. 

7.  The  upper  and  lower  beds  of  all  stone,  both  facing  and  backing, 
must  be  rough-axed,  and  cut  true  and  parallel  to  each  other,  so  as  to  bear 
the  straight  edge  all  over,  and  allow  of  half-inch  joints;  but  the  cutting 
need  not  be  fine.  Square  and  parallel  cutting  of  the  beds  will  be  in- 
sisted upon.  No  hollow  or  slack  cutting  or  falling  away  towards  the 
rear  will  be  permitted.  . 

No  plug-holes  will  be  allowed  more  than  nine  inches  in  diameter,  or 
more  than  l£  inches  deep,  nor  within  one  foot  of  each  other,  or  of  the 
edge  of  the  stone. 

8.  The  vertical  joints  of  the  face-stone  must  be  cut  sufficiently  true  to 
make  half-inch  joints.  They  must  be  cut  square  with  the  face  for  a  dis- 
tance back  of  at  least  two  feet.  The  rear  part  of  the  stone  shall  in  no 
case  project  beyond  the  jointed  portion  ;  and  all  headers  shall  be  jointed 
hack  three  feet  on  each  side.  They  must  in  all  cases  be  perfectly  plumb, 
and  at  right  angles  to  the  plane  of  the  bed. 

9.  The  vertical  sides  of  the  backing  must  be  good  quarry  splits,  with 
no  projections  greater  than  4  inches. 

The  blocks  of  backing  may  vary  in  contents  from  20  to  80  cubic  feet; 
the  whole  lower  bed,  and  at  least  three-fourths  of  the  upper  bed  being 
equal  in  quality  of  cutting  to  that  prescribed  for  the  face-stone. 

10.  The  rear  faces  of  stretchers  may  be  left  rough  as  they  come  from 
the  quarry.  It  will  not  be  insisted  upon  that  they  shall  be  parallel  to  the 
front  faces,  although  this  is  preferred. 

Headers  must  run  back  full  width  for  at  least  half  their  length ;  the 
tail,  however,  may  be  wider  than  the  front,  and  their  rear  faces  may  be 
left  as  they  come  from  the  quarry. 

11.  The  best  bed  of  every  stone  must  be  the  bottom  bed,  and  the  lewis- 
holes  must  be  put  in  the  top  bed  in  every  case. 


54 

12.  All  stones  must  be  cut  full  to  the  rise  named  in  the  plans. 

In  each  course  there  will  be  a  tail-bond  at  each  re-entrant  angle  of  the 
paasonry ;  and  also  up  to  course  D,  inclusive,  at  the  inner  angles  of  the 
tunnels.  When  these  stones  are  headers  they  must  be  long  enough  to 
make  a  good  bond.  In  all  cases  they  must  be  properly  jointed  back,  and 
exposed  portions  of  their  faces  left  rock-faced  as  on  other  face-stone. 

13.  Courses  Z  to  D,  inclusive,  will  have  ten  granite  corners  each,  and 
course  E  will  have  six  such  corners. 

The  face-stone  of  course  F  are  to  be  granite  throughout,  except  over 
the  spandrel  courses  of  the  front  or  curtain  arches,  and  a  portion  of  the 
rear  face. 

Courses  G  and  H  are  to  be  granite-faced,  except  a  portion  of  the  front 
and  rear  of  each. 

The  curtain  arches  are  also  to  be  of  granite.  The  granite  for  these  is 
not  included  in  these  specifications.  Wherever  the  limestone  facing 
comes  adjacent  to  granite  facing  of  any  kind  it  must  be  jointed  back  to 
the  full  extent  required  by  the  plans. 

Special  elevations  of  the  spandrel  courses,  and  courses  over  the  arches 
are  given  in  the  plans. 

All  these  stones  are  to  be  plumb-faced. 

The  sides  of  course  D  are  partly,  and  of  course  E  entirely,  made  up  of 
stone  with  the  upper  bed  sloped  §  inch  per  foot  run.  These  stones  must 
each  be  carefully  cut  to  the  dimensions  given  and  plainly  marked  with 
letter  and  number. 

14.  There  are  two  semi-circular  arches  running  through  the  front  por- 
tion of  the  masonry.  Each  of  these  is  laid  up  in  three  separate  por- 
tions, two  of  27  feet  each,  and  one  of  26  feet  7  inches  length;  thus  mak- 
ing six  distinct  arches. 

The  radius  of  the  intrados  is  11  feet  6  inches,  and  that  of  the  ex- 
trados  14  feet  6  inches. 

The  outer  faces  of  the  archstone  may  be  left  as  they  come  from  the 
quarry.  The  ends  and  beds  must  be  pointed  off  sufficiently  true  to  allow 
of  half-inch  joints. 

The  intrados.  is  to  be  left  rock-face,  but  must  have  a  two-inch  chisel 
draft,  carried  entirely  around  the  face  of  each  stone. 

The  voussoirs  of  the  arches  need  not  be  cut  to  the  exact  lengths  given 
in  the  drawings,  provided  that  the  total  lengths  are  made  up  in  each 
course.  But  no  variations  of  more  than  six  inches  will  be  allowed  from 
the  drawings  ;  and  every  archstone  must  be  plainly  marked  with  its 
numbtr  and  letter. 

15.  Every  stone  must  have  a  lewis-hole  of  a  clear  depth  of  4£  inches, 
and  a  width  in  direction  of  thickness  of  lewis,  of  J  inch. 

A  sample  flat  lewis  will  be  furnished  to  the  contractor,  and  ail  holes 
must  be  cut  so  as  to  allow  of  its  use. 
No  round  lewis-holes  will  be  permitted. 


55 


All  lewis-holes,  especially  in  the  archstones,  must  be  so  placed  that 
when  the  stoues  are  suspended  they  will  be  in  the  right  position  for  set- 
ting.   All  re-cutting  will  be  charged  to  the  contractor. 

1 6.  In  case  any  mistakes  are  made  in  the  cutting  of  the  stone,  as  re- 
gards the  character  of  the  beds  or  joints,  or  in  the  rise,  or  if  there  are 
other  gross  violations  of  the  provisions  of  these  specifications,  the  con- 
tractor is  distinctly  notified  that  such  stone  will  be  either  wholly  con- 
demned and  thrown  back  on  his  hands,  or  else  a  proportionate  reduction 
in  the  price  will  be  made ;  the  same  being  at  the  option  of  the  Engineer. 

Condemned  face-stone,  if  received  at  all,  will  be  reckoned  as  backing. 

17.  The  stone  are  to  be  delivered  at  the  wharves  of  the  Trustees,  at 
Red  Hook. 

Steam  power,  for  unloading  vessels,  will  be  furnished  by  the  Board  of 
Trustees;  six  unloading  derricks  being  provided  at  the  edge  of  the  wharf. 
The  crews  of  the  vessels  must  assist  in  uuloading.  They  must  bring 
the  stone  under  the  boom  of  the  derrick,  and  must  attach  the  hoisting 
block  to  the  lewis,  and  furnish  all  labor  that  is  required  on  board  the  ves- 
sels for  unloading  as  rapidly  as  tli3  Trustees  may  require. 

18.  The  first  course  of  stone  must  be  delivered  by  November  15,  or 
before,  and  the  balance  at  the  rate  of  one  course  per  week,  in  the  order 
of  the  numbers.  As  it  is  of  the  utmost  importance  that  the  delivery  of 
the  stone  be  prompt  and  iu  the  order  of  the  courses,  this  rate  of  delivery 
will  be  insisted  upon;  and  if  there  are  any  delays  in  the  delivery  from 
any  came  whatever,  the  stone  will  be  obtained  elsewhere,  and  the  atten- 
dant expense  will  be  charged  to  the  contractor,  together  with  all  damages 
arising  from  delays. 

19.  Parties  proposing  must  be  known  as  men  both  skilled  in  the  quarry- 
ing and  cutting  of  stone,  as  well  as  prompt  and  reliable  in  their  business 
transactions,  and  must  bring  satisfactory  references  to  that  effect,  as  well 
as  to  their  financia^  responsibility. 

20.  Auy  question  as  to  the  intent  or  meaning  of  these  specifications 
shall  be  referred  to  the  Engineer,  whose  decision  shall  be  final. 

21.  The  Board  of  Trustees  reserve  to  themselves  the  right  to  reject  any 
or  all  bids  offered,  and  to  make  awards  of  separate  portions  of  the  total 
quantities  required,  if  to  their  interest  so  to  do.  They  also  reserve  the 
right  to  increase  the  quantity  of  backing  required  beyond  the  amount 
heretofore  named  in  this  specification,  provided  it  be  required  to  complete 
this  portion  of  the  New  York  Anchorage. 

22.  Bids  will  be  received  as  follows: 

LIMESTONE. 

For  899  cubic  yards  Face-stone,  delivered,  per  cubic  yard   $.  . . . 

For  731         '*         Arch  Sheeting,  delivered,  per  cubic  yard   $. ... 

For  1,000      u        Cut  Backing,  delivered,  per  cubic  yard   $. . . . 


56 


23.  Monthly  estimates  will  be  made  on  or  about  the  10th  day  of  each 
month,  for  stone  delivered  during  the  previous  month,  provided  that  no 
stone  will  be  estimated  for  until  all  courses  below  them  are  completed. 
Payments  will  be  made  on  these  estimates  after  deducting  15  per  cent., 
said  deduction  to  be  kept  as  a  guarantee  for  the  satisfactory  performance 
of  the  contract,  and  to  be  paid  in  one  month  from  the  time  the  contract 
is  completed.  In  making  these  estimates  the  cubic  contents  of  the  stone 
will  be  taken,  except  that  the  rock-face  projections  will  not  be  allowed 
for.  Archstone  will  be  measured  net,  at  three  feet  thickness  of  arch, 
except  that  projections  on  top,  in  excess  of  this,  will  be  paid  for  as  backing. 

26.  Proposals  will  be  addressed  to  the  Trustees  of  the  New  York  and 
Brooklyn  Bridge,  Brooklyn,  N.  Y.,  indorsed  "  Proposals  for  Anchorage 
Stone." 

W.  A.  ROEBLING, 

Engineer. 


SPECIFICATIONS  FOR  CORNERS,  FACING  AND  ARCHSTONE, 
OF  GRANITE,  REQUIRED  FOR  THE  NEW  YORK 
ANCHORAGE,  EAST  RIVER  BRIDGE,  1875. 

1.  Proposals  will  be  received  until  12  M.,  October  9th,  1875,  for  the 
delivery  of  85  yards  of  Granite  Corner-stone;  250  yards  Cut  Face-stone  ; 
and  31  yards  Arch  Face-stone,  all  of  Granite. 

2.  The  quantity  is  composed  in  nine  courses  of  masonry,  as  follows  : 

No.  of        To  be  Rise  of  Granite  Granite 

Course.      Marked.  Course.  Corners.  '     Face-stone.  Total 

29   Z   28   in  18  yds  

30   A    24   in  12  '•   

31   B    28   in   17  "   

32   C    24  in  12    "  ?  

30   in   10  "   

33    D   J    20   in   3  "   


32   in   4  "   

34   E    35£  in   9  "   

35   F   26   in   94  yds. 

36   G    26   in   81  " 

37   H    24   in   75  " 

Totals  85  cub.  yds.  250  cub.  yds. 

RECAPITULATION. 

Total  Granite  Corners   85  cubic  yds. 

"       "        Cornice  "  V  "  Course   94 

"       "       Cornice  Bevel  Courses   156  " 

Archstone   31  " 

Total  Granite  required   336  cubic  yds. 


57 


3.  Detail  drawings  on  a  scale  of  five  feet  to  the  inch,  will  be  furnished 
for  every  course.  Special  drawings  will  be  furnished  for  the  corner- 
stones and  archstones,  and  templates  for  each  archstone. 

4.  Every  stone  must  be  plainly  marked  on  delivery,  with  its  appropri- 
ate letter  and  number  as  given  on  the  plans. 

5.  Every  stone  must  be  cut  full  to  the  dimensions  given,  and  no  allow- 
ances made  for  joints  or  beds,  as  this  has  already  been  done. 

The  bottom  bed  is  the  one  the  measurements  refer  to  in  every  case, 
except  where  specially  mentioned,  and  allowances  must  be  made  for  bat- 
ter or  projections  accordingly. 

6.  Courses  Z  to  D  have  10  granite  corners  in  each,  and  course  E  has 
six.  Of  these  all,  but  the  two  rear  ones  in  D,  and  those  in  E,  must  have 
the  beds  cut  true  and  parallel,  one  to  the  other,  and  must  be  out  full  to 
the  rise  named  for  each.  The  upper  bed  of  corners  excepted  above,  must 
be  sloped  §  inch  per  foot  run,  as  shown  in  the  plans. 

The  beds  of  all  the  face-stone  in  courses  F,  G  and  H  must  also  be 
parallel.  The  beds  of  all  stone  must  bear  the  straight  edge  all  over,  so 
as  to  allow  of  half-inch  joints,  but  the  cutting  need  not  be  fine.  No 
hollow  or  slack  cutting  will  be  permitted. 

No  plug-holes  of  over  9  inches  in  diameter,  or  more  than  l£  inches 
deep,  nor  within  one  foot  of  each  other,  or  of  the  edge  of  the  stone,  will 
be  permitted. 

7.  All  vertical  joints  must  be  sufficiently  true  to  make  half-inch  joints. 
They  must  be  cut  square  with  the  face  for  the  full  width  of  the  stone  in 
the  case  of  stretchers;  and  in  the  case  of  headers  they  must  be  jointed 
back  for  the  full  width  of  the  adjacent  stretchers. 

8.  For  the  corner-stone  the  vertical  joints  shall  be  at  right  angles  to 
the  plane  of  the  beds.  For  the  cornice  courses  F,  G  and  H,  they  must 
be  cut  so  as  to  be  vertical  when  the  bed  is  sloped  §  inch  per  foot  run,  as 
shown  in  the  elevations  of  each  course. 

9.  The  rear  faces  of  stretchers  and  headers  may  be  left  rock-face.  If 
they  exceed  the  dimensions  ^iven  in  the  plans,  however,  the  excess  will 
be  paid  for  as  backing. 

10.  The  best  bed  of  every  stone  must  be  the  bottom  bed. 

11.  The  Granite  must  be  uniform  in  color,  sound  and  durable,  free  from 
all  cracks,  weak  spots  or  sap,  and  without  seams  of  any  kind. 

12.  Each  corner-stone  has  a  four-inch  projection,  which  is  made  by 
cutting  a  chamfer  entirely  around  each  face,  except  at  the  projecting 
corner,  which  is  left  square.  The  chamfer  must  be  fine  cut.  The  sur- 
face between  the  chamfers  must  be  pointed  to  a  uniform  surface,  with  a 
projection  of  £  inch,  and  a  l£  inch  chisel  draft  cut  entirely  around  each 
face.  Each  face  has  a  batter  of  £  inch  per  foot  rise,  and  the  measure- 
ments refer  to  the  bottom  bed,  the  four-inch  projection  being  in  addition 
to  the  same. 


58 


13.  Two  Granite  arches  are  required.  These  are  semi-circular,  with  a 
radius  of  intrados  of  11  feet  6  inches,  and  length  in  direction  of  the  axis 
of  three  feet  each.  A  special  drawing  and  template  will  be  furnished 
for  each  archstone. 

The  intrados  of  each  stone  must  be  smooth  pointed. 

The  exterior  face  of  each  (except  where  it  is  hidden  by  the  buttress 
masonry),  is  to  have  a  l£  inch  draft  entirely  around  it,  cut  to  a  depth  of 
1  inch.    The  raised  panels  thus  formed  is  to  be  smooth  pointed. 

The  beds  and  rear  face  are  to  be  cut  true,  but  may  be  rough  pointed. 

The  Keystones  are  to  have  a  three-inch  draft  around  each  face,  cut  to 
a  depth  of  three  inches,  and  the  panel  thus  made  is  to  be  smooth  pointed. 
The  exposed  portions  of  the  sides  and  the  top  of  the  key-stones  and  the 
intrados  are  also  to  be  smooth  pointed. 

14.  Courses  F,  G-  and  H  are  to  be  cut  to  dimension,  and  the  beds  and 
joints  as  previously  mentioned.  A  clean  1^-inch  draft  is  to  be  cut  around 
every  face  except  the  >  projection  in  course  F.  The  space  within  the 
draft  is  to  have  half-inch  projection,  and  be  smooth  pointed,  and  the  > 
projection  finished  smooth. 

Samples  of  the  work  can  be  seen  at  the  anchorages. 

15.  The  top  bed  of  every  stone  must  be  lewised  for  a  sample  flat  lewis, 
which  will  be  furnished  to  the  contractor.  Every  lewis-hole  must  have  a 
clear  depth  of  4^  inches,  and  a  width  in  the  direction  of  the  thickness  of 
the  lewis,  of  ^  inch. 

All  lewis-holes,  especially  in  the  archstones,  must  be  so  placed  that 
when  the  stones  are  suspended  they  will  be  in  the  right  position  for  set- 
ting.   All  re-cutting  will  be  charged  to  the  contractor. 

16.  In  case  any  mistakes  are  made  in  the  cutting  of  the  stone,  as  re- 
gards the  character  of  the  beds  or  joints,  or  in  the  rise,  or  if  there  are 
other  gross  violations  of  the  provisions  of  these  specifications,  the  con- 
tractor is  distinctly  notified  that  such  stone  will  be  either  wholly  con- 
demned and  thrown  back  on  his  hands,  or  else  a  proportionate  reduction 
in  the  price  will  be  made ;  the  same  being  at  the  option  of  the  Engineer. 

Condemned  stone,  if  received  at  all,  will  be  reckoned  as  backing. 

17.  The  stone  are  to  be  delivered  at  the  wharves  of  the  Trustees  at 
Red  Hook. 

Steam  power,  for  unloading  vessels,  will  be  furnished  by  the  Board  of 
Trustees ;  six  unloading  derricks  being  provided  at  the  edge  of  the 
wharf.  The  crews  of  the  vessels  must  assist  in  unloading.  They  must  bring 
the  stone  under  the  boom  of  the  derrick,  and  must  attach  the  hoisting- 
bloek  to  the  lewis,  and  furnish  all  labor  that  is  required  on  board  the  ves- 
sels for  unloading  as  rapidly  as  the  Trustees  may  require. 

18.  The  first  course  of  stone  must  be  delivered  by  November  15th,  or 
before,  and  the  balance  at  the  rate  of  one  course  per  week,  in  the  order 


59 


of  the  numbers.  As  it  is  of  the  utmost  importance  that  the  delivery  of 
the  stone  be  prompt,  and  in  the  order  of  the  courses,  this  rate  of  delivery 
will  be  insisted  upon  ;  and  if  there  are  any  delays  in  the  delivery,  from 
any  cause  whatever,  the  stone  will  be  obtained  elsewhere,  and  the  atten- 
dant expenses  will  be  charged  to  the  contractor,  together  with  all  damages 
arising  from  delays. 

19.  Parties  proposing  must  be  known  as  men  both  skilled  in  the  quar- 
rying and  cutting  of  stone,  as  well  as  prompt  and  reliable  in  their  busi- 
ness transactions,  and  must  bring  satisfactory  references  to  that  effect, 
as  well  as  to  their  financial  responsibility. 

20.  Any  question  as  to  the  intent  or  meaning  of  these  specifications 
shall  be  referred  to  the  Engineer,  whose  decision  shall  be  final. 

21.  The  Board  of  Trustees  reserve  to  themselves  the  right  to  reject  any 
or  all  bids  offered,  and  to  make  awards  of  separate  portions  of  the  total 
quantities  required,  if  to  their  interest  so  to  do. 

22.  Bids  will  be  received  as  follows  : 

GRANITE. 

For  85  cubic  yds.  Granite  Corners,  delivered,  per  cubic  yd   $  ... 

For  31  cubic  yds.  Archstone,  delivered,  per  cubic  yd   $  

For  94  cubic  yds.  V  course  of  Cornice,  delivered,  per  cubic  yd   $  

For  156  cubic  yds.  Bevel  courses,  delivered,  per  cubic  yd   $. .  . . 

23.  Monthly  estimates  will  be  made  on  or  about  the  10th  day  of  each 
month  for  stone  delivered  during  the  previous  month,  provided  that  no 
stone  will  be  estimated  for  until  all  courses  below  them  are  completed. 
Payments  will  be  made  on  these  estimates  after  deducting  15  per  cent., 
said  deductiou  to  be  kept  as  a  guarantee  for  the  satisfactory  performance 
of  the  contract,  and  to  be  paid  in  one  month  from  the  time  the  contract 
is  completed. 

In  making  these  estimates  the  net  cubic  contents  of  the  stone  will  be 
taken,  estimated  according  to  the  exact  dimensions  of  the  plans 

24.  Proposals  will  be  addressed  to  the  Trustees  of  the  New  York  and 
Brooklyn  Bridge,  Brooklyn,  N.  Y.,  indorsed  "  Proposals  for  Anchorage 
Stone." 

W.  A.  ROEBLING, 

En  gineer. 


SPECIFICATIONS  FOR  SADDLES   AND   SADDLE-PLATES  FOR 
THE  BROOKLYN   AND   NEW   YORK   TOWERS,  EAST 
RIVER  BRIDGE,  1874. 

1.  Proposals  are  invited  by  the  undersigned  up  to  October  1,  1874,  for 
the  delivery  of  eight  cast-iron  Saddles  and  eight  cast-iron  Saddle-plates  for 
the  Brooklyn  and  New  York  Towers  of  the  East  River  Suspension  Bridge. 


60 


2.  Each  Saddle  will  weigh  about  25.000  pounds;  four  of  the  Saddle- 
plates  will  weigh  about  22,000  pounds  each,  and  lour  about  19,000  pounds 
each:  thus  making  a  total  weight  of  at  least  18  2  tons. 

SADDLES. 

3.  The  object  of  the  Saddles  is  to  furnish  a  bearing  with  easy  vertical 
curves  upon  which  the  main  cables  and  a  portion  of  the  main  stays  may 
rest  in  passing  over  the  pier.  In  plan,  they  are  rectangular  13  feet  by  4 
feet  1  inch  over  all ;  extreme  height,  4  feet  3  inches,  and  the  main  portion 
4  inches  thick. 

Over  the  centre  of  each,  one  of  the  cables  passes  through  a  groove  19^ 
inches  wide  and  17^  inches  deep  at  its  middle  section. 

On  each  side  of  the  main  groove  are  two  smaller  grooves,  in  each  of 
which,  four  of  the  long  stays  are  placed. 

The  ends  and  edges  of  the  grooves  are  all  rounded  wherever  there  is 
possibility  of  chafing  of  the  wires. 

Seventeen  openings  are  made  underneath  the  grooves,  to  reduce  weight 
and  secure  uniformity  in  thickness  as  far  as  possible. 

4.  The  longitudinal  edges  are  carried  one  inch  below  the  under  surface 
of  the  Saddle  to  make  end  bearings  for  iron  rollers,  upon  which  the  whole 
will  rest. 

The  inner  faces  of  these  edges  must  be  planed  true;  the  under  surface 
must  also  be  planed  true,  very  smooth,  and  so  as  to  bear  a  straight  edge  in 
any  direction.  For  this  purpose  the  contractor  must  make  sufficient  allow- 
ance in  the  pattern,  as  the  dimensions  given  are  to  be  those  of  the  fin- 
ished Saddle. 

5.  The  outside  of  the  two  longitudinal  edges  must  be  true — that  is,  per- 
fectly parallel  and  i4  out  of  wind,''  and  free  from  roughness,  but  need  not 
be  planed. 

6.  The  grooves  must  also  be  free  from  roughness,  but  need  not  be  fin- 
ished. 

SADDLE-PLATES. 

7.  The  Saddle-plates  are  to  rest  in  seats  prepared  in  the  masonry,  and 
form  perfectly  true  beds,  upon  which  the  rollers  supporting  the  Saddles 
may  traverse. 

They  are  to  be  16  feet  2  inches  long,  14f  inches  high  over  all,  the 
outside  ones  8  feet  wide  at  the  centre  and  6  feet  3  inches  at  the  ends; 
and  the  inside  ones  6  feet  6  iuches  wide  at  the  centre.  The  same  pattern 
answers  for  the  inner  ones  by  cutting  a  strip  from  one  side.  The  central 
portion  is  to  be  4^  inches  thick,  and  the  sides  3^  inches  thick,  when  fin- 
ished. 

There  are  two  lugs  in  each  side  channel  to  which  stays  will  be  attached. 
At  the  ends  of  the  side  channels  as  well  as  the  main  channel,  all  the 
edges  are  to  be  rounded  off  to  prevent  chafing. 


61 


8.  The  central  channel  is  to  have  its  surface  planed  perfectly  true, 
very  smooth,  and  so  as  to  bear  a  straight  edge  all  over.  The  edges  which 
form  end  bearings  for  the  rollers  are  also  to  be  planed  true.  The  verti- 
cal sides  of  the  main  ribs  on  the  face  towards  the  rollers  must  be  perfectly 
parallel,  and  must  be  planed  true. 

9.  Sufficient  allowance  must  be  made  in  the  pattern  for  planing,  in  all 
cases. 

10.  The  edges  of  the  central  plates,  where  cut  off,  are  to  have  a  rough 
cut  of  say  &  inch  to  insure  their  being  true  and  parallel,  but  need  not  be 
planed  smooth. 

GENERAL  SPECIFICATIONS. 

11.  Complete  detail  drawings,  which  form  a  part  of  these  specifications, 
will  be  furnished  the  contractor,  and  the  castings  are  to  conform  to  them 
in  measurement  when  planed  and  ready  for  delivery. 

12.  All  angles  are  to  be  filleted,  except  those  abutting  the  ends  of  the 
rollers. 

13.  As  soon  as  the  castings  can  be  removed  from  the  sand,  cleaned  and 
dressed  off,  they  are  to  receive  a  thorough  coat  of  raw  linseed  oil.  Alter 
this  is  hardened,  a  second  coat  of  boiled  linseed  oil  is  to  be  applied. 

After  the  planing  is  completed,  the  planed  surfaces  are  to  be  coated 
with  tallow  and  white  lead. 

14.  The  contractor  is  to  make  all  patterns,  do  all  the  planing  and  fin- 
ishing required,  and  deliver  the  finished  castings  either  at  the  Tower 
wharves,  East  river,  or  in  the  yard  at  base  of  the  Towers. 

15.  The  patterns  are  to  be  the  property  of  the  Bridge  Company  when 
the  work  is  completed. 

16.  The  quality  of  the  iron  must  be  tough  and  strong.  In  order  to 
test  this,  the  contractor  will  be  required  to  cast  at  least  six  sample  bars 
from  the  same  melting  used  in  the  plates.  They  must  be  5  feet  long,  1 
inch  square,  and  when  placed  on  supports  4  feet  6  inches  apart,  must 
break  with  no  less  than  a  central  load  of  500  pounds. 

Trial  bars  of  the  metal  proposed  to  be  used  must  also  be  furnished  the 
Engineer  for  experiment,  before  the  plates  are  cast. 

17.  The  castings  must  be  sound  throughout,  free  from  air  bubbles,  cold 
shuts,  strains  or  cracks ;  and  in  order  to  insure  freedom  from  strains, 
they  must  lie  a  sufficient  time  in  the  sand  to  insure  slow  cooling. 

18.  It  is  hereby  distinctly  understood  that  the  contractor  takes  all  risks 
of  any  cracks  appearing  in  the  castings  which  may  arise  from  strains,  due 
either  to  hasty  cooling,  shrinkage,  or  the  shape  of  the  patterns.  If  any 
of  the  castings  should  crack  from  any  of  these  causes  within  one  month 
after  their  acceptance,  it  is  understood  that  they  will  be  replaced  by  the 
contractor ;  injuries  resulting  from  accidents  while  in  the  hands  of  the 
Bridge  Company  excepted. 


62 


19.  Before  the  plates  will  be  accepted  they  must  he  subject  to  the  in- 
spection of  the  Engineer,  or  his  authorized  assistant,  at  the  foundry. 

20.  The  bid  for  the  castings  will  be  so  much  per  pound  for  the  Saddles 
complete,  and  so  much  per  pound  for  the  Saddle-plates  complete,  all  de- 
livered, or  a  bid  may  be  made  for  the  whole  lot  at  one  price ;  and  no  bids 
will  be  received  from  such  foundries  as  have  not  heretofore  made  cast, 
ings  approximating  these  in  size  and  weight. 

21.  The  Bridge  Company  reserves  the  right  to  reject  all  or  any  of  the 
bids  offered. 

22.  The  plates  will  be  required  first,  and  the  delivery  must  begin  by 
December  10th,  and  must  be  completed  before  the  1st  of  February,  1875. 

23.  Monthly  payments  will  be  made  about  the  10th  of  each  month  for 
all  work  delivered  during  the  previous  month,  reserving  fifteen  per  cent, 
until  the  completion  of  the  contract. 

24.  Bids  are  to  be  marked  on  the  outside  of  the  envelopes,  "  Proposals 
for  Saddles  and  Saddle-plates,"  and  addressed  to  the  "  New  York  Bridge 
Co.,  No.  21  Water  street,  Brooklyn,  N.  Y." 

W.  A.  ROEBLING, 
Chief  Engineer  N.  T.  Bridge  Co. 


SPECIFICATION  FOR  ANCHOR  PLATES,  NEW  YORK  ANCHOR- 
AGE, EAST  RIVER  BRIDGE,  1875. 

1.  Proposals  are  invited  by  the  undersigned  up  to  April  15,  1875,  for 
the  delivery  of  four  cast-iron  anchor  plates  for  the  New  York  anchorage 
of  the  East  River  Suspension  Bridge. 

2.  Each  plate  will  weigh  about  46,000  pounds,  making  a  total  weight 
of  92  tons  for  the  four  plates 

3.  The  general  shape  of  the  plate  is  that  of  an  oval  spider,  17  feet  6 
inches  by  16  feet,  and  2  feet  6  inches  in  depth.  It  has  16  arms,  com- 
posed of  heavy  ribs  and  flanges.  The  centre  of  the  plate  has  18  open- 
ings for  the  passage  of  a  double  set  of  anchor  chains.  These  openings 
are  separated  by  ribs  3  inches  thick  and  15  inches  long,  and  extending 
the  full  depth  of  the  plate  2  feet  6  inches.  The  sides  of  the  ribs  must 
be  true  and  perpendicular,  and  out  of  wind.  After  the  plate  is  cast,  a 
pattern  bar  must  pass  easily  through  the  openings.  Plans  may  be  seen 
at  the  Engineer's  office,  21  Water  street,  Brooklyn. 

4.  The  upper  surface  of  the  plate  must  be  a  true  surface,  and  out  of 
wind  throughout  its  entire  extent. 

5.  The  semi-circular  grooves  at  the  bottom  of  the  ribs  must  be  straight 
and  true.  A  5-inch  pin  must  be  fitted  to  them,  so  as  to  bear  uniformly 
at  every  point,  and  lie  parallel  to  the  upper  face  of  the  plate. 

6.  Two  of  the  plates  will  have  the  three  arms  on  one  side,  cut  two 
foot  shorter.    This  must  be  done  so  as  to  make  the  plates  "  right  and 


63 


left,"  in  other  words,  cut  from  opposite  ends.  These  two  plates  will  be 
cast  last. 

7.  The  quality  of  the  iron  must  be  tough  and  strong.  Such  a  mixture 
of  iron  should  be  used  as  will  give  great  tensile  strength,  because  the 
uplifting  strain  of  the  anchor  chains  is  such  as  to  produce  a  tensile  strain 
in  the  upper  flange  of  the  arms,  tending  to  break  them  off. 

The  casting  must  be  sound  throughout,  free  from  air  bubbles,  cold 
shuts,  t trains  or  cracks. 

8.  In  order  to  test  the  quality  of  the  iron,  the  contractor  will  be  re- 
quired to  cast  two  or  more  sample  bars  from  the  same  melting  used  in 
the  plates.  They  must  be  5  feet  long,  1  inch  square,  and,  when  placed 
on  supports  4  feet  6  inches  apart,  must  break  with  no  less  than  500 
pounds  placed  in  the  middle. 

9.  Such  trial  bar3  of  the  metnl  proposed  to  be  used  by  the  contractor, 
must  also  be  furnished  to  the  Engineer  for  experiment  before  the  plates 
are  cast. 

10.  In  order  to  insure  freedom  from  strains,  due  to  rapid  cooling,  the 
castings  must  lie  in  the  sand  for  one  week  before  uncovering. 

11.  Before  the  plates  will  be  accepted  they  must  be  subject  to  the  in- 
spection of  the  Engineer  or  his  authorized  assistant,  at  the  foundry. 

12.  The  castings  are  to  be  delivered  with  the  flat  side  up,  on  deck  of  a 
scow  or  vessel,  at  the  New  York  tower  wharf,  East  river. 

13.  It  is  hereby  distinctly  understood  that  the  contractor  takes  all 
risks  of  any  cracks  appearing  in  the  casting,  which  may  arise  from 
strains,  due  either  to  hasty  cooling,  shrinkage,  or  the  shape  of  the  pat- 
tern. If  the  plate  should  crack  from  any  of  these  causes  within  one 
month  after  the  acceptance,  it  is  understood  that  the  contractor  will  fur- 
nish a  new  one. 

Injuries  resulting  from  accidents  while  in  the  hands  of  the  Bridge 
Company  excepted. 

14.  The  pattern  will  be  furnished  by  the  Bridge  Company  at  the 
Brooklyn  Anchorage. 

15.  The  bid  for  the  castings  will  be  so  much  per  pound,  delivered. 

16.  The  castings  must  be  delivered  by  July  1st,  1875. 

17.  No  bids  will  be  accepted  except  from  such  foundries  as  have 
heretofore  made  castings  approximating  these  in  size  and  weight. 

18.  Payment  will  be  made  by  the  Bridge  Company  in  one  month  after 
lelivery  of  plates. 

19.  Bids  to  be  marked  "  Proposals  for  anchor  plates,"  on  outside  of  en- 
velopes, and  directed  to  the  "  New  York  Bridge  Company,  21  Water 
street,  Brooklyn,  N.  Y." 

W.  A.  ROEBLINGr. 

Engineer  Neiu  York  Bridge  Company. 


64 


SPECIFICATIONS    FOR    IROX    ANCHOR    BARS.   NEW  YORK 
ANCHORAGE,  EAST  RIVER  BRIDGE,  APRIL,  1875. 

1.  Proposals  are  invited  up  to  April  19,  1875,  for  the  delivery  of  about 
1,027,000  pounds  of  iron,  anchor  bars  and  about  30.000  pounds  iron 
pins,  for  the  New  York  Anchorage,  East  River  Suspension  Bridge. 
These  bars  embrace  the  entire  chains  for  this  Anchorage. 

2.  An  inspection  of  the  plan  shows  4  sets  of  chains  arrauged  in  a 
curved  position,  and  comprising  10  sets  of  links  connected  by  pins  in 
each.  Each  set  of  chains  is  double,  consisting  of  2  tiers  of  links,  one 
above  the  other,  and  secured  at  the  bottom  to  one  anchor  plate. 

3.  The  total  contract  comprises  : 

Sets.  Weighing. 
1  2  3  j200  bars»  wittl  a  section  in  tne  body  of  the  bar,  7  in.  by  3  in.)  231  Q00  lbg 

4  5  6  /216  bars,  with  a  section  in  the  body  of  the  bar,  8  in.  by  3  in.)  294  0Q0  lbs 
'  ♦  ■ )  24  u  **  "  11         8     "    ly  )  ' 

7,8,9  (216  bars,  with  a  sectioninthebodyof  thebar,  9in.  by3in.)  ,,M  nftft  ,ho 
&10.   \184  »  "  "  "  9       "   1%  )  5UU>0U0 1DS- 


Total  S56  bars  1,0-25,000  lbs. 

4  bars.  S  inches  by  1  inch,  about   2.000  lbs. 

80  pins,  about   30,000  lbs. 

4.  The  different  sets  of  links  and  pins  will  consist  of  the  following 

sizes  and  lengths : 


Position  Sizes 
of  of 

Links.  No.  Bars. 

-  of  - 

Chains.  Bars,  inches. 


No.  1  )    28    7  X3 

Upper.) 

No.  1  ) 
Lower.) 

No.  2. ) 


Length  of 
Bars. 
C.  to  C.  of  eyes. 

13  ft.   9  in. 


7X1^ 
7  X3 


Sizes  of 
holes  m  heads. 

for  5  in.  pins. 


No. 
ot 
Pins. 

|  4  pins. 


Lengths 
Sizes  of  of 
Pins.  Pius. 

in.diam.  5S  in. 


Upper.) 

No.  2. ) 
Lower. ) 

No.  3. ) 
Upper.  ( 

No.  3. ) 
Lower.  / 

No.  4.  • 
Upper. 

No.  4.' 
Lower. 

No.  5. 
Upper. 

No.  5. 
Lower. 

No.  6  s 
Upper. 

No.  6. 
Lower. 

No.  7. ' 
Upper. 

No.  7. ' 
Lower. 

No.  8. ' 
Upper. 

No.  8. ' 
Lower. 

Mo.  9/ 
Upper. 

No.  9. ' 
Lower. 


32  7x3 

32   7  x3 
8  7x1^ 


I  X3 

12  ft.  10 

y 13  ft 

40  8  X  3  12  ft.  10 
36  8X3 


36   7  X 

32  8  X3 
8  8X 


13  ft.  3y  in.  for  5   in.  pins 
in.        "  " 


(4  pins. 


qi/  in  /One  5  in.  and 
ui.  \  one  6  in.  pin. 


for  6  in.  pins. 


13  ft.  3> 

36  Sx3  12  ft.  10 
8   8x1^    12  ft,  10 

8x3   )1Qf.    9iv  in    /One  6  in.  and 
avivC  i6Jl-       m-  \one  &y  in.  pin.  j 


in. 

in. 


8  8x1^/ 

8  11    }  12  ft.  10 


8  . 

9  xi 


in. 


/One  6^"  in. and) 
(  one  7  in.  pin./ 


13  ft.  3}£  in. 

36  9  x3       12  ft.  10  in. 

8  9x1^    12  ft.  10    in.  "  " 

32  9  x3  "  /See  paragraph  for  7  in.  pin. 

8  9  x  ly  \No.5  astolgth  "  " 

40  9x3       12  ft.  10    in.  "  " 

36  9  x3       13  ft.    Zy  in.  "  " 

8  9X1^       "          "  "  " 

36  9  x3         "         **  "  " 

8  9x1^ 


"       "       5Sy  M 

"       "      63%  " 

5  in.diam.  61%  " 

«     "     m% " 

6  in.  diam.  64%  " 
"  "  69%  " 
u  "  64%  « 
"       "      69%  " 

6%  in.  diam.  64%  " 
"      "      75  " 

7  in.  diam.  65  " 
H  "  69%  " 
"  "  68  " 
"  "  69% H 
"  "  68  " 
«       «<      69%  " 


No.  10.   152   9  xl^      17  ft.  5    in.        "  " 

5.  The  length  of  the  link  No.  8,  in  the  upper  chain,  cannot  be  deter- 
mined until  the  lower  bars  of  the  same  link  are  set  in  place.    They  will 


65 


probably  be  a  little  longer  than  13  feet  3^  inches,  but  will  not  exceed  13 
feet  6  inches,  so  that  the  iron  can  be  rolled  of  the  latter  length,  in  ad- 
vance, if  desired. 

6.  Each  bar  will  be  forged  with  a  head  at  each  end,  and  inasmuch  as 
the  sizes  and  shapes  of  heads  vary  according  to  the  mode  of  upsetting 
employed,  such  shape  will  be  determined  on  by  the  Engineer  after  the 
contract  is  let;  provided,  however,  that  the  dimensions  shall  be  such  as, 
with  the  form  employed,  will,  in  the  judgment  of  the  Engineer,  give  a 
strength  of  head  equal  to  that  of  the  body  of  the  bar. 

7.  The  heads  must,  in  all  cases,  be  upset  on  the  solid  bar,  and  not 
welded  on.  All  heads  of  one  size  must  be  of  a  uniform  and  regular  out- 
line. They  must  be  forged  smooth  and  flat.  The  bar,  as  well  as  the 
head,  must  be  out  of  wind,  and  not  bent  to  one  side  or  twisted.  The  thick- 
ness of  the  head  must  not  exceed  that  of  the  bar  by  more  than  £  of  an 
inch,  and  in  no  case  must  it  be  less  than  the  bar  in  thickness.  The  heads, 
on  set  Xo.  1  must  be  as  nearly  as  possible  of  the  exact  thickness,  as  it 
will  be  impossible  otherwise  to  pass  them  through  the  anchor  plates. 

Particular  attention  is  called  to  this  section,  for  the  reason  that  in  every 
case  before  the  insertion  of  any  set  of  bars  (after  the  first)  the  preceding 
set  is  rigidly  fixed  in  the  masonry,  and  the  intent  is  to  leave  the  smallest 
possible  space  between  the  sides  of  the  heads. 

8.  Each  chain  has  a  width  of  about  6  feet,  and  each  pin  passes  through 
from  17  to  31  bars.  It  is,  therefore,  essential  that  the  bars  be  drilled 
exactly  at  right  angles  to  their  length,  and  with  absolute  exactness  as  re- 
gards the  distance  between  the  holes,  so  that  the  pins  may  pass  at  right 
angles  through  the  sets  when  in  position. 

An  important  point  to  be  observed  here  is,  that  the  heads  shall  not  be 
sprung  when  clamped  in  the  drill  press,  otherwise  the  holes  will  not  be  at 
right  angles  to  the  bars,  and  the  pins  will  bind  in  them  when  the  bars 
are  placed  in  position. 

9.  The  holes  must  all  be  drilled  with  a  play  of  1-32  of  an  inch ;  that 
is,  with  a  diameter  1-32  of  an  inch  in  excess  of  that  given  for  the  pin. 

10.  The  Engineer  will  make  the  following  test,  as  to  length,  of  each 
set  of  bars:  Nine  b?.rs  of  the  set,  selected  at  random,  shall  be  laid  over 
each  other,  aud  separated  by  three-inch  blocks,  and  the  proper  pins 
passed  simultaneously  through  the  two  ends  without  difficulty. 

All  the  bars  shall  be  at  the  same  temperature  while  making  the  test. 

The  contractor  shall  furnish  the  labor  and  facilities  for  making  the 
tests,  and  shall  retain  at  least  two  pins  of  each  diameter,  until  the  tests 
have  been  made. 

PINS. 

11.  The  pins  will  be  turned  oft"  so  as  to  gauge  throughout  their  length 
to  the  exact  diameter  mentioned,  the  allowance  for  driving  having  been 
mack-  in  the  pin-holes. 

To  facilitate  driving,  the  pins  must  have  the  angles  at  the  ends  slightly 
rountlod. 

5 


66 


12.  The  pins  must  be  of  hammered  iron,  and  must  be  equal  in  quality 
to  that  in  the  bars. 

13.  The  Bridge  Company  reserve  the  right  to  reject  any  or  all  bids,  or 
to  award  portions  of  the  total  quantity  to  different  contractors.  In  case 
this  be  done,  the  lots  will  be  as  follows:  sets  1,  2  and  3  in  the  first;  sets 
4,  5,  6  in  the  second,  and  the  remainder  in  the  third  lot. 

The  contractor  for  any  lot  succeeding  the  first,  will  be  furnished  with 
a  template  of  the  pins  in  the  upper  end  of  the  set  preceding,  so  as  to  in- 
sure the  certainty  that  these  pins  will  fit  the  holes  he  has  to  drill. 

QUALITY  OP  IRON  AND  TESTING. 

14.  The  iron  shall  be  that  known  as  "double  refined."  It  shall  be 
perfectly  sound,  and  free  from  all  blemish,  either  in  the  original  bars,  or 
after  the  heads  are  made,  such  as  burning,  unsound  welding,  or  cracks  of 
any  kind. 

Its  breaking  strength  shall  be  not  less  than  50,000  pounds  per  square  inch. 

For  the  purpose  of  testing  this,  the  Engineer  shall  have  the  right  to 
select  at  random  one  or  more  bars  from  each  lot  of  those  provided  for 
each  set  of  links.  Prom  the  bar  so  selected,  the  contractor  shall  cut  out 
three  test  pieces,  one  near  the  centre,  and  one  near  each  end. 

These  pieces  shall,  without  working  of  any  kind,  be  turned  down  to 
fit  some  standard  testing  machine,  and  so  as  to  give  a  uniform  section  of 
one  inch  diameter  for  six  inches  of  length. 

The  average  breaking  strength  of  these  specimens  may  be  considered 
the  strength  of  the  bar. 

They  shall  stretch  in  breaking  at  least  ten  per  cent,  of  their  length, 
and  shall  bear  a  strain  of  20,000  pounds  per  square  inch,  without  per- 
manent set. 

If  the  test  on  the  first  bar  be  satisfactory,  no  other  bar  of  that  lot  will 
probably  be  tested  (provided  the  iron  is  all  from  the  same  maker,  and  the 
Engineer  is  satisfied  with  the  appearance  of  the  remainder  of  the  bars), 
and  the  contractor  may  proceed  with  the  manufacture  of  the  links. 

If  the  first  test  be  unsatisfactory,  more  tests  will  be  made,  and  the 
Engineer  shall  have  the  right  to  reject  all  the  bars  of  any  lot,  should  he 
have  reason,  after  a  sufficient  number  of  tests,  to  consider  the  iron  un- 
reliable. He  may  also  reject  the  links  after  manufacture,  if  the  eyes  are 
not  properly  made,  or  the  iron  has  been  injured  in  making  them. 

The  contractor  shall  furnish  the  extra  bars  for  these  tests  without 
charge. 

It  will  be  seen  this  will  require  at  least  ten  additional  bars  in  all  to  be 
furnished. 

Bars  injured  in  rolling  or  in  making  the  heads  may  be  used  for  making 
tests  from,  so  that  the  expense  for  extra  bars  will  be  small. 

It  is  understood  that  the  object  of  these  tests  is  to  insure  a  sound, 
tough  iron,  in  the  finished  work.  Testing  enough  to  insure  this  will  be 
insisted  upon,  and  no  mji  e. 


67 


16.  In  addition  to  this  test,  the  1£  inch  bars  shall  each  be  tested  by 
the  contractor  to  a  strain  of  20,000  pounds  per  square  inch  of  section. 
Such  bars  as  show  a  permanent  set  under  this  strain  shall  be  rejected. 

17.  All  tests  shall  be  made  at  the  expense  of  the  contractor,  and 
under  the  direction  of  the  Engineer  of  the  Bridge  Company,  or  his 
authorized  assistant,  the  contractor  to  supply  the  testing  machine  and 
the  requisite  labor. 

18.  All  bars  are  to  be  delivered  on  board  of  a  vessel  or  lighter,  at 
the  New  York  Tower  wharf,  and  are  to  be  unloaded  with  the  assistance 
of  the  crew,  the  Bridge  Company  furnishing  the  power  and  derricks. 

19.  The  links  in  set  No.  1  must  be  furnished  by  July  1st;  those  in  set 
No.  2  by  July  15th,  and  the  remainder  at  the  rate  of  one  set  per  month  ; 
the  delivery  being  completed  by  April  1st,  1876. 

20.  The  Bridge  Company  will  make  payments  in  current  funds  on  the 
10th  day  of  every  month,  for  all  pins  and  bars  delivered  during  the  pre- 
vious mouth,  10  per  cent,  of  the  contract  price  being  retained  until  the 
completion  of  the  contract.  When  the  contract  is  completed,  and  all  the 
bars  are  delivered,  a  final  payment,  including  the  back  percentage,  will 
be  made  on  the  10th  of  the  ensuing  month. 

21*.  Proposals  will  be  addressed  to  the  New  York  Bridge  Company, 
No.  21  Water  street,  Brooklyn,  N.  Y.,  marked  "Proposals  for  Anchor 
Bars  and  Pins." 

W.  A.  ROEBLING, 
Chief  Engineer  New  York  Bridge  Co. 


SPECIFICATIONS  FOR  WIRE   ROPES  FOR  THE  EAST  RIVER 

BRIDGE. 

1.  Proposals  will  be  received  until  the  first  day  of  February,  1876,  for 
the  manufacture  and  delivery  of  the  following  Steel  and  Iron  Wire 
Ropes,  required  for  the  erection  of  the  temporary  foot-bridge,  cradle  cables 
and  other  appliances  necessary  for  the  construction  of  the  main  cables 
of  the  East  River  Suspension  Bridge. 

The  lengths  and  sizes  of  the  rope  are  as  follows  : 

L— STEEL  ROPES. 

2.  (a.)  Two  (2 J  galvanized  steel  foot-bridge  ropes,  each  rope  to  weigh  12 
lbs.  per  foot  and  to  be  scant  2£  inches  in  diameter,  with  a  breaking  strength 
of  not  less  than  240  net  tons. 

The  lengths  are  uneven,  as  follows  : 

One  rope  to  be  3,625  feet  long. 

The  second  rope  to  be  3,688  feet  long. 

(b.)  Three  (3)  galvanized  steel  cradle  ropes,  each  weighing  91bs.  per 
foot,  and  to  be  lull  2\  inches  in  diameter.  Each  of  these  ropes  has 
a  length  of  3,625  feet,  and  a  breaking  strength  of  not  less  than  18  tons. 


68 


(c.)  One  (1)  galvanized  steel  carrier  rope,  weighing  3  lbs.  per  foot,  arid 
being  about  If  inches  in  diameter,  having  a  length  of  3,710  feet,  and  a 
breaking  strength  of  not  less  than  60  tons. 

(<?.)  Four  (4)  galvanized  steel  working  ropes  (for  pulling  over  wires), 
weighing  f  lb.  per  foot,  and  being  f  inch  in  diameter,  each  rope  having  a 
length  of  3,800  feet,  and  a  breaking  strength  of  not  less  than  than  18 
tons. 

(e.)  Four  (4)  galvanized  steel  pendulum  ropes  (for  separating  strands), 
weighing  f  lb.  per  foot,  and  having  a  diameter  of  11-16  of  an  inch.  Each 
rope  has  a  wire  core,  and  a  length  of  3,700  feet. 

II.— IRON  ROPES. 

(f.)  Two  (2)  galvanized  iron  hand-rail  ropes,  composed  of  seven  wires 
to  the  strand,  No.  17  gauge,  with  a  tarred  Manila  core  and  ordinary  lay, 
not  too  long.    Length  of  each  rope  3.500  feet. 

(g.)  Under-floor  foot-bridge  guys.  They  have  an  aggregate  length  of 
10,868  feet,  and  a  thickness  of  11-16  of  an  inch.  The  rope  to  be  compos- 
ed of  six  strands  around  a  hemp  centre,  and  to  weigh  f  lb.  to  the  foot. 
Each  strand  must  have  seven  wires,  No.  15  gauge,  galvanized,  and  made 
of  best  (b.  b.)  charcoal  iron. 

(7i.)  Suspender  cords,  weighing  9  feet  to  the  pound,  and  consisting  of 
one  strand  of  seven  No.  14  galvanized  charcoal  wires.  An  aggregate 
length  of  8,000  feet  will  be  wanted. 

CONSTRUCTION  OF  ROPES. 
3.  (a.)  The  foot-bridge  ropes  will  be  composed  of  six  strands,  laid 
around  a  central  core,  all  of  equal  size.  The  outside  strands  will  contain 
19  wires  each,  but  the  core,  in  place  of  being  a  strand,  will  be  a  regular 
laid  rope,  composed  of  six  strands  and  a  core,  each  containing  seven 
wires.  The  wires  of  this  rope  core  must  be  of  the  proper  size,  so  as  to 
give  it  the  same  diameter  as  the  strands.  The  lay  of  the  rope  core  must 
be  the  same  as  the  lay  of  the  outside  strands,  which  may  be  either  right 
lay  or  left  lay.  The  size  of  the  various  wires  must  be  so  proportioned 
as  to  give  a  total  weight  of  12  lbs.  per  foot.  No  projecting  wires  can  be 
allowed  in  the  strands.  The  strands  must  be  round.  The  lay  of  these 
ropes  will  be  that  known  as  long  lay ;  that  of  the  strands  in  the  rope 
being  not  less  than  one  turn  in  17^  inches,  nor  more  than  one  turn  in  1  Sc- 
inches. 

(b.)  The  construction  of  the  cradle  ropes  will  be  similar,  viz. :  Six  outer 
strands  around  a  centre.  Each  outer  strand  will  contain  19  wires,  and 
the  central  strand  will  be  the  same  as  the  outer  ones,  differing  in  that 
respect  trom  the  foot-bridge  ropes.  The  size  of  wires  must  be  pro- 
portioned, to  give  a  weight  of  9  lbs.  per  foot  to  the  rope.  The  lay  of 
these  ropes  will  also  be  long  lay;  not  less  than  one  turn  in  14j  inches, 
nor  more  than  one  turn  in  15^  inches. 

(c.)  The  carrier  rope  will  be  composed  of  six  strands  around  a  wire 


69 


centre,  each  strand  containing  7  wires,  No.  9  gauge.  The  lay  of  the  rope 
will  be  moderately  long,  about  one  turn  in  9  inches. 

(d.)  Each  working  rope  will  be  composed  of  six  strands  of  seven  No. 
14  wires  each,  laid  around  a  central  core  of  best  tarred  hemp.  As  these 
ropes  are  intended  for  running  ropes,  they  must  have  a  moderately  short 
lay  of  about  one  turn  in  6£  inches ;  and,  as  these  ropes  are  to  be  spliced 
into  endless  ropes,  they  must  all  have  the  same  lay. 

(e.)  The  pendulum  ropes  will  be  composed  of  seven  No.  15  wires  in 
each  strand,  with  a  wire  centre,  and  made  in  the  same  way  as  the 
carrier  rope.  The  lay  will  be  moderately  long,  about  one  turn  in  65- 
inches. 

(/.)  The  construction  of  the  iron  ropes  is  sufficiently  described  in  par- 
agraph 2.  under  the  headings /,  g  and  h. 

STRENGTH  AND  QUALITY  OP  STEEL  WIRE  TO  BE  USED. 
4.  All  the  steel  ropes  are  to  be  made  of  the  best  quality  of  hardened  and 
tempered  galvanized  crucible  cast-steel  '*  wire.  No  "  Bessemer  "  wire, 
or  "  Siemens-Martin  "  steel  wire,  or  "  Open  Hearth  "  steel  wire  can  be 
accepted.  The  strength  required  is  at  the  rate  of  160,000  lbs.  per  square 
inch  of  section.  This  rate  is  not  excessive,  and  can  easily  be  obtained 
by  manufacturers  of  such  wire.  It  requires,  for  instance,  that  No.  7 
wire,  weighing  12  feet  to  the  pound,  shall  have  a  breaking  strength  of 
4.6 00  oo=3,966  lbs..    No.  8  wire,  weighing  15  feet  to  the  pound,  shall 

3  •  3  6  x  1  2 

have  a  breaking  strength  of  not  less  than  ^0.0  0.0. =35 175  lbs.  No.  9 
wire,  weighing  17  feet  to  the  pound,  shall  have  a  breaking  strength  of 
not  less  than  J^Qg<lo_o==2.384  lbs.,  etc.,  etc. 

Specimen,  with  this  breaking  strength,  must  stretch  at  least  2  per 
cent.,  and  must  have  a  limit  of  elasticity  not  less  than  §  of  the  breaking 
strength — that  is  to  say,  a  sample  of  wire  stretched  up  to  f  of  its  break- 
ing strength  must  recover  itself  without  any  appreciable  permanent  set. 
When  the  manufacturer  has  prepared  a  sufficient  quantity  of  wire  for 
these  ropes,  he  must  notify  the  Engineer  or  his  authorized  assistant,  who 
will  test  a  sufficient  quantity  of  the  wire  to  see  if  it  comes  up  to  the 
above  standard.  He  will  continue  these  tests  from  time  to  time,  in  order 
to  insure  a  uniformity  throughout  the  manufacture.  All  these  tests  will 
be  made  after  the  wire  is  galvanized,  and  not  before.  The  manufacturer 
must  furnish  the  testing  machine  for  this  purpose.  The  necessities  of 
the  case  require  that  all  our  ropes  must  be  suspended  with  a  very  small 
deflection.  The  strain  is  consequently  very  great,  arisiug  as  much  from 
their  own  weight  as  from  the  load  placed  upon  them.  An  increase  in 
the  size  of  the  ropes  would,  therefore,  increase  the  margin  of  safety  but 
little,  and  we  are  compelled  to  rely  entirely  upon  the  superior  quality  of 
the  material  used  in  order  to  be  safe. 

The  rates  of  strength  in  the  Nos.  7,  8  and  9  wires  are  given  as  ex- 
amples. The  precise  weight  of  wire  must  be  determined  by  the  manufac. 
turer,  so  as  to  produce  the  weight  per  foot  of  rope  specified.  Where 


70 


nothing:  is  said  to  the  contrary,  the  Birmingham  wire  gauge  is  understood 
to  be  standard. 

5.  All  the  steel  wire  used  in  these  ropes  must  be  properly  soldered  with 
brass  solder:  no  other  kind  of  joint  can  be  allowed.  This  joint  must  be 
galvanized,  so  that  there  is  no  interruption  in  the  continuity  of  the  zinc 
covering.  In  no  case  will  it  be  permitted  to  stick  in  the  ends  of  the  wire 
loose  in  place  of  the  proper  joint.  Inasmuch  as  the  size  of  wire  used  is 
very  coarse,  the  rings  will  be  small  and  joints  very  plenty.  It  is,  there- 
fore, required  that  rings  weighing  not  less  then  501bs.  shall  be  used. 

6.  In  order  to  diminish  the  stretch  of  these  ropes  as  much  as  possible, 
it  is  desirable  they  should  be  laid  up  under  great  strain,  at  least  one-tenth 
of  the  breaking  strain.    This  strain  must  be  uniform  on  all  the  strands. 

7.  All  these  ropes,  as  well  as  strands,  must  be  made  in  one  piece,  of 
the  whole  length  required,  and  in  no  case  can  the  splicing  of  a  whole 
strand  be  permitted. 

GALVANIZING. 

8.  All  the  wires  used  in  these  ropes  must  be  completely  and  thorough- 
ly galvanized.  This  is  a  very  important  matter,  as  the  durability  of  the 
ropes  depends  entirely  upon  it.  The  ropes  will  be  subjected  to  the  direct 
influence  of  salt  air,  not  only  during  their  temporary  use,  but  also  when 
used  as  stays  in  the  permanent  work.  Some  of  the  smaller  ropes  will 
even  be  dragged  through  the  salt  water.  The  galvanizing  must  therefore 
not  only  be  very  perfect  on  the  wire,  but  great  care  must  be  taken  not  to 
scrape  any  oft'  in  manufacturing  the  ropes. 

The  Inspector  appointed  for  the  Trustees  will  incpect  the  wire  before 
it  is  laid  in  the  rope,  and  reject  all  rings  which  show  uncovered  spots, 
scales,  cracks  after  bending,  or  other  imperfections  in  the  coating  of  zinc. 

Another  important  point — for  the  consideration  of  the  manufacturer 
alone — is  to  have  the  steel  wire  galvanized  in  such  a  manner  as  not  to 
diminish  the  temper,  hardness  or  breaking  strength  tnereof.  The  Trustees 
of  the  Bridge  are  fully  protected  in  this  respect,  because  the  wire  will  be 
tested  only  after  it  is  galvanized. 

9.  Each  of  the  four  working  ropes,  as  described  in  paragraphs  2  and  3, 
under  heading  (d),  is  to  be  marked  by  the  manufacturer  with  a  promi- 
nent mark,  such  as  paint,  or  a  wire  wrapping,  to  designate  the  point  at 
which  these  ropes  will  rest  on  the  top  of  the  New  York  Tower.  This 
poiut  will  come  at  a  distance  of  1,070  feet  from  the  outer  end  of  the 
rope  as  it  lies  coiled  on  the  reel,  or  its  equivalent  distance  of  2,730  feet 
from  the  inner  end  of  the  rope. 

10.  The  ropes  will  be  wanted  in  the  following  order  :  First,  the  four 
working  ropes  (d)  ;  next,  the  carrier  rope  (c) ;  next,  one  cradle  rope  (b) ; 
next,  two  foot-bridge  ropes  («);  next,  the  two  cradle  ropes  (b);  next,  the 
under-ttoor  guys  and  suspenders  (g)  and  (A) ;  next,  the  hand-rail  ropes 
(/);  and,  lastly,  the  four  pendulum  ropes  (e).  All  these  ropes  must  be 
delivered  in  three  months  after  the  letting  of  this  contract. 


71 


11.  All  the  ropes  must  be  mounted  or  coiled  on  strong  vertical  reels, 
with  extra  thick  wooden  sides,  provided  with  an  opening  for  a  horizontal 
spindle  on  which  to  revolve  them.  The  side  of  the  reel  must  be  of  extra 
width,  to  admit  of  the  application  of  breaks  in  paying  off.  Reels  must 
be  made  of  extra  strength  and  size,  so  as  not  to  be  smashed  by  the  great 
weight  of  the  ropes  in  handling  and  moving  them.  The  reels  will  be 
paid  for  extra.  In  no  case  can  these  ropes  be  received  in  a  loose  coil, 
because  they  have  to  be  transported  through  crowded  streets  of  a  city. 
A  coil  is,  moreover,  unsuited  in  other  respects  for  handling  the  rope. 

12.  These  ropes  may  be  delivered  either  directly  at  the  New  York 
Anchorage,  or  on  board  of  a  boat,  lighter  or  scow,  at  Pier  29,  East  river, 
where  the  Trustees  of  the  Bridge  will  do  the  unloading.  If  delivered  on 
a  scow,  they  must  be  loaded  on  deck,  resting  on  heavy  timbers.  The 
deck  of  the  scow  must  be  strong  enough  to  stand  the  moving  of  the 
heavy  load.  It  also  must  be  high  enough  to  be  even  with  the  dock  at 
mean  high  water.  The  four  working  ropes  must,  in  any  case,  be  deliver- 
ed at  Pier  29. 

13.  Payment  will  be  made  in  current  funds,  on  the  10th  of  every 
month,  for  all  ropes  delivered  and  accepted  during  the  preceding  month. 
Bids  to  be  made  at  so  much  a  lb.,  in  currency,  lor  each  of  the  different 
sizes. 

Proposals  must  be  addressed  to  the  "  Board  of  Trustees  of  the  New 
York  and  Brooklyn  Bridge,"  21  Water  street,  Brooklyn. 

Bids  will  only  be  entertained  from  parties  of  reputation  and  experience 
in  the  manufacture  of  wire  rope,  and  who  have  ample  facilities  for  execut- 
ing this  contract  in  time. 

W.  A.  ROEBLING, 
Engineer  Neic  York  and  Brooklyn  Bridge. 


SPECIFICATIONS  FOft  STEEL  CABLE  WIRE,  FOR  THE  EAST 
RIVER  SUSPENSION  BRIDGE. — 1876.* 

1.  Sealed  proposals  will  be  received  by  the  Trustees  of  the  New  York 
and  Brooklyn  Bridge,  up  to  the  1st  d<:y  of  December,  1876,  for  the 
manufacture  and  delivery  in  Brooklyn,  N.  Y.,  of  3,400  net  tons  or 
6.800,000  lbs.  of  Steel  Cable  Wire,  for  the  East  River  Suspension 
Bridge. 

2.  For  the  information  of  parties  living  abroad  it  may  be  stated,  that 
the  East  River  Bridge  will  connect  the  two  cities  of  New  York  and 


•These  specifications  are  inserted  here  exactly  as  they  were  originally  issued, 
but  the  following  has  to  be  noted,  namely : 

The  figure  of  29,000,000  was  used  as  the  modulus  in  the  calculations  for  the 
tests  in  paragraphs  10  and  5. 

In  the  foot  note  the  words  "  one-third  of  its  strength  is  taken  up  In  supporting 
Its  own  weight,"  should  have  read  '*one  seventeenth  (l-17th)  of  Its  strength,  etc.' 


72 


Brooklyn,  which,  are  separated  from  each  other  by  an  arm  of  the  sea, 
called  the  East  river.  That  the  Bridge  has  one  main  span  of  1,000 
ft.,  and  two  side  spans  of  930  ft.  each,  besides  approaches  at  each 
end,  making  a  total  length  of  more  than  one  mile.  The  main  floor  is 
suspended  by  4  cables,  each  15  in.  in  diameter,  each  cable  composed 
of  6,300  parallel  laid  wires,  which  are  laid  up  in  place,  and  it  is  for 
the  manufacture  of  these  cables  that  the  steel  wire,  called  for  in  these 
specifications,  is  required. 

3.  The  general  character  of  the  wire  is  as  follows:  it  must  be  made 
of  steel ;  it  must  be  hardened  and  tempered ;  and,  lastly,  it  must  all 
be  galvanized. 

4.  The  size  of  the  wire  shall  be  No.  8  full,  Birmingham  Gauge.  A 
length  of  14  ft.  must  weigh  exactly  1  lb.  before  it  is  galvanized,  but 
the  weight  of  the  galvanized  wire  is  taken  in  making  up  the  3,400 
tons. 

5.  Each  wire  must  have  a  breaking  strength  of  no  less  than  3,400 
lbs.  This  corresponds  in  wire  weighing  14  ft.  to  the  lb.,  to  a  rate  of 
160,000  lbs.  per  sq.  in.  of  solid  section.  The  elastic  limit  must  be  no 
less  than  .^4^  of  the  breaking  strength,  or  1,600  lbs.  Within  this 
limit  of  elasticity,  it  must  stretch  at  a  uniform  rate  corresponding  to 
a  modulus  of  elasticity  of  not  less  than  27,000,000  nor  exceeding  29.- 
000,000.  The  quality  of  the  wire,  in  regard  to  its  stretching,  is  fur- 
ther alluded  to  under  the  head  of  "  Tests." 

QUALITY  OF  WIRE.* 

6.  The  rods  of  which  the  wire  is  made,  must  be  of  a  superior  qual- 
ity of  steel,  suitable  for  wire  purposes.  It  is  not  implied  that  the 
highest  priced  steel  shall  be  used,  such  as  is  required  for  fine  cutlery, 
springs,  or  the  like,  but  it  is  only  a  superior  steel  rod,  which  will 
make  a  wire  that  comes  up  to  the  standard  here  laid  down. 

*  Note.— It  may  not  be  amiss  here  to  present  a  few  of  the  reasons  which  led 
to  the  selection  of  the  size  and  quality  of  steel  wire  adopted  in  these  specifica- 
tions. In  all  previous  bridge  cables,  charcoal  iron  wire  of  either  No.  10  or  No.  9 
gauge  was  used.  In  iron  wire  it  is  well  known  that  a  remarkable  increase  in 
strength  is  developed  by  the  process  of  cold  drawing.  Thus  a  bar  1  inch  square, 
having  a  strength  of  40,000  or  50,000  lbs.  to  the  square  inch,  will  show  a  rate  of 
from  90,000  to  100,000  lbs.  per  square  inch  of  section,  when  drawn  down  to  No.  9 
or  No.  10  size.  In  steel,  this  is  also  true  to  a  moderate  extent,  while  the  process 
of  tempering  and  hardening  still  farther  increases  the  strength.  The  use  of 
this  size  has  three  advantages.  The  first  is,  that  fewer  wires  are  required  to  make 
up  the  cable,  thus  reducing  labor.  The  second  is,  that  its  greater  weight  offers 
greater  resistance  to  the  wind— a  most  important  consideration  when  hiving  a 
cable  in  a  locality  as  exposed  as  the  present  one.  The  third,  that  it  offers  less 
comparative  surface  to  rust.  The  use  of  a  size  much  coarser  than  No.  S  is,  how- 
ever, barred  by  the  extreme  stiffness  of  the  material,  making  it  very  troublesome 
to  handle. 

In  the  question  of  strength,  as  regards  the  choice  between  using  iron  and  the 
various  grades  of  steel  for  cables,  we  find  that  the  great  length  of  the  main  span 


73 

In  case  the  billets  or  rods  are  not  made  by  the  contractor  for  the  wire, 
it  is  to  be  understood  that  the  inspector,  on  the  part  of  the  Trustees,  is  to 
have  ample  facility  to  satisfy  himself,  by  ocular  proof,  that  they  are  ac- 
tually made  out  of  suitable  steel,  and  from  uniform  stock. 

H  ARDENING  AND  TEMPERING. 

7.  The  standard  called  for  in  these  specifications,  demands  that  this 
steel  wire  shall  be  of  a  uniform  medium  quality ;  that  is,  it  must  be  nei- 
ther too  hard  or  high  in  its  character,  nor  too  soft  or  low  in  its  temper. 
In  order  to  insure  this  uniform  quality,  it  is  necessary  that  all  the  cable 
wire  shall  undergo  the  operation  of  hardening  and  tempering.  The  par- 
ticular manner  in  which  this  operation  shall  be  performed  is  not  pre- 
scribed here,  but  is  left  free  to  the  manufacturer.  There  are  at  least  four 
methods  known  to  the  Engineer,  all  of  which  can  produce  good  results,  if 
properly  adapted  to  this  size  of  wire.  Some  of  these  processes  are  con- 
trolled by  patents;  others  are  of  a  secret  nature.  Whatever  the  process 
pursued  by  the  manufacturer  may  be,  the  Engineer,  or  his  inspector,  must 
have  satisfactory  evidence  that  every  ring  of  wire  has  undergone  this 
operation.  At  the  same  time,  the  manufacturer  must  not  lose  sight  of 
the  fact  that  the  wire  is  to  be  galvanized,  after  beiug  hardened  and  tem- 
pered. It  is  not  intended,  however,  that  this  paragraph  shall  be  an  abso- 
lute bar  to  an}r  other  mode  or  process  of  manufacture  of  the  steel  and 
steel  wire,  provided  the  requirements  in  the  foregoing  paragraphs  are 
strictly  fulfilled  ;  it  being  believed,  at  the  same  time,  that  only  the  opera- 
tion of  hardening  and  tempering  will  produce  such  wire. 

GALVANIZING. 

8.  The  cables  of  the  East  River  Bridge  are  suspended  directly  over  a 
salt  water  stream,  and  are,  in  addition,  exposed  to  the  salt  air  of  the 
neighboring  sea-shore.  Experience  has  shown  that  the  ordinary  means 
of  protection,  such  as  paint,  oil  or  varnish,  which  would  be  ample  in 

at  once  excludes  the  use  of  iron  or  the  lower  grades  of  steel.  Even  with  the 
quality  called  for  in  these  specifications,  one-third  of  the  strength  is  taken  up  in 
supporting  its  own  weight ;  hence  the  use  of  iron  wire  bearing  ouly  90,000  lbs. 
per  square  inch,  or  of  the  lower  grades  of  steel,  is  not  admissible,  because  it 
would  necessitate  a  cable  of  such  weight  and  size  that  it  would  become  unman- 
ageable, and  involve  the  greatest  difficulties  in  making  it.  I,  at  least,  would  not 
be  willing  to  undertake  it.  The  rate  of  strength  decided  upon,  namely,  160,000 
lbs.  to  the  square  inch,  represents  a  fair  mean  of  all  the  objects  that  it  is  desira- 
ble to  attain.  It  is  true  that  steel  wire  of  a  very  much  higher  rate  of  strength 
can  be  made.  Its  use  would  produce  a  cable  much  smaller  than  15  inches  in  di- 
ameter. Now  it  is  just  as  undesirable  to  have  too  small  a  cable  as  too  large 
a  one.  A  certain  bulk  of  cable  is  absolutely  necessary  in  order  to  give  a  mass, 
and  the  inertia  to  resist  dangerous  oscillations  in  the  cable  itself.  I  would  fur- 
thermore state,  that  the  dimensions  of  the  anchor  chains,  the  sizes  of  the  saddles 
and  plates,  the  weight  of  the  anchorages  and  the  shapes  of  the  towers,  have  all 
been  proportioned  for  a  cable  15  inches  in  diameter,  and  made  of  steel  wire  of 
the  strength  above  given.  W.  A.  R, 


* 


74 

the  interior,  are  totally  inadequate  to  prevent  rusting,  in  localities  so 
near  the  coast.  The  only  certain  safeguard  is  a  coating  of  zinc,  which 
acts  by  its  absolute  air-tightness,  as  well  as  by  its  galvanic  action, 
and  is  not  easily  abraded. 

The  galvanizing  must  be  done  throughout,  in  a  thorough  and  per- 
fect manner ;  each  ring  will  be  inspected  in  this  regard  by  the  inspector, 
when  he  tests  the  wire.  All  rings  will  be  rejected  which  show  spots 
imperfectly  covered,  or  are  full  of  rough  lumps,  showing  a  defective 
stripping.  The  galvanizing  must  be  of  uniform  thickness,  and  must 
not  scale  off,  or  show  any  cracks,  when  the  wire  is  bent. 

The  attention  of  the  manufacturer  is  particularly  called  to  the  point 
that  he  must- galvanize  at  such  a  temperature  and  in  such  a  manner 
as  not  to  destroy  the  temper  of  the  wire.  The  manufacturer  must 
run  the  whole  risk  in  this  respect,  because  the  wire  is  inspected  and 
tested  after  it  has  been  galvanized.  Samples  which  have  been  received 
and  tested,  show  that  it  is  not  difficult  to  reconcile  these  two  opera- 
tions, and  that  when  proper  caution  is  exercised,  and  the  parties  pos- 
sess sufficient  experience,  the  wire  can  be  properly  galvanized  without 
impairing  the  temper. 

STRAIGHT  WIRE. 

9.  All  the  wire  called  for  in  these  specifications  must  be  ''straight" 
wire ;  that  is  to  say,  when  a  ring  is  unrolled  upon  the  floor  the  wire 
behind  must  lie  perfectly  straight  and  neutral,  without  any  tendency 
to  spring  back  in  the  coiled  form,  as  is  usually  the  case.  This  straight 
condition  must  not  be  produced  by  the  use  of  straightening  machines 
of  any  kind,  as  they  only  injure  the  strength  and  elasticity  of  the 
wire.  As  the  cables  can  only  be  laid  up  with  straight  wires,  this 
necessity  is  obvious. 

To  produce  straight  wire  it  is  necessary  to  lead  the  wire  from  a 
point  within  the  galvanizing  trough  in  a  straight  line,  under  consider- 
able tension  to  the  guide  sheave  or  winding  drum,  and  to  locate  the 
sheave  or  drum  at  such  a  distance  as  to  permit  the  wire  to  be  cooled  and 
set  before  it  is  coiled  thereon.  And  also  to  make  the  sheave  or  drum  of 
such  size  as  will  not  cause  a  permanent  bending  of  the  cooled  wire.  Any 
method  of  cooling  the  wire  more  rapidly  will  permit  of  a  less  distance 
between  the  trough  and  drum.  As  the  process  above  described  has  been 
patented,  the  Trustees  of  the  bridge  have  arranged  with  the  patentee  in 
reference  to  all  the  wire  called  for  in  these  specifications,  so  that  parties 
furnishing  said  wire  will  not  be  required  to  pay  a  royalty  thereon. 

MODE  OF  TESTING. 

10.  Owing  to  the  uncertain  character  of  steel,  and  the  percentage  of 
rejection  that  usually  attends  the  finished  product,  notwithstanding  all 
the  care  and  the  amount  of  selection  it  may  have  undergone  in  the 


75 


various  stages  of  its  manufacture,  the  Engineer  considers  it  absolutely 
necessary  that  every  ring  should  undergo  a  test  when  finished. 
There  will  be  four  kinds  of  tests. 

Firstly. — One  ring  in  every  forty  (40)  will  be  tested,  as  follows:  a 
piece  of  wire,  sixty  (60)  feet  lorg,  will  be  cut  off  from  either  end  of  the 
ring,  and  it  will  be  then  placed  in  a  vertical  testing  machine.  An  initial 
strain  of  400  lbs.  is  now  applied,  which  should  take  out  every  crook  and 
bend.  A  vernier  gauge,  capable  of  being  read  to  —  l.—-^  of  one  foot,  is  so 
attached  as  to  indicate  the  stretch  of  50  feet  of  the  wire.  Successive  in- 
crements of  400  lbs.  strain  are  then  applied,  and  the  vernier  read  each 
time,  until  a  strain  of  1,600  lbs.  is  reached. 

The  conditions  now  are  as  follows:  that  the  amount  of  stretch  for  each 
of  these  increments  shall  be  the  same,  and  that  the  total  stretch  between 
the  initial  and  terminal  strains  shall  not  be  less  than  y^-g-  of  one  foot, 
equal  to   J-9i       of  the  50  feet.    And  furthermore,  on  reducing  the 

^  10  0.000  '  e 

strain  to  1,200  pounds  there  shall  be  a  permanent  elongation  not  exceed- 
ing:   '  „1  *  of  its  length. 

°  TTTo.oolT  ° 

The  same  wire  will  then  be  subjected  to  a  breaking  strain,  and  the 
total  amount  of  stretch  noted.  The  minimum  strength  required  is  3,400 
lbs.,  equal  to  an  ultimate  strength  of  160,000  lbs.  per  square  inch.  The 
minimum  stretch,  when  broken,  shall  have  been  2  per  cent,  in  50  feet,  and 
the  diameter  of  the  wire  at  the  point  of  fracture  shall  not  exceed  ^.tJ^ 
of  one  inch. 

Secondly. — One  ring  out  of  every  five  shall  be  tested  by  having  a  pkce  6 
feet  long  cut  off,  and  placed  in  a  testing  machine  with  vernier  guage,  so 
attached  and  graduated  as  to  read  the  stretch  of  5  feet  of  length  to 
^_JL_.  of  one  foot.  When  strains  shall  be  applied  in  the  foregoing  or- 
der,  and  the  vernier  read  at  each  point  respectively,  if  the  results  corres- 
pond with  the  requirements  for  the  50  feet  lengths,  as  regard  modulus 
and  limit  of  elasticity  and  ultimate  strength,  and  the  stretch  of  5  feet  of 
length  exceed  3£  per  cent,  of  its  length,  the  ring  will  be  accepted ;  other- 
wise it  will  be  rejected. 

Thirdly. — Every  ring  will  be  tested  by  having  a  piece  16  inches  long 
cut  from  either  end,  and  placed  in  a  testing  machine,  having  a  vernier 
guage  so  arranged  as  to  include  one  foot  in  length  of  the  wire,  and  shall  be 
graduated  as  finely  as  practicable.  Each,  piece  will  be  subjected  to  the 
same  strains  mentioned  for  the  5  feet  lengths,  and  the  results  must  cor- 
respond with  the  requirements  before  mentioned,  excepting  that  of  the 
ultimate  stretch. 

These  shorter  pieces  are  used  to  expedite  the  testing,  and  to  economize 
wire;  but  tjie  requirements  mentioned  in  connection  with  the  50  feet 
tests  will  be  insisted  on,  and  any  doubt  as  to  results  with  the  shorter  pieces 
may  be  solved  by  testing  a  piece  50  feet  long.  And  in  case  one  ring  in 
forty  (40)  should  not  be  a  sufficient  test  of  the  quality,  then  the  inspector 


76 


can  select,  at  closer  intervals,  rings  for  50  feet  tests.  If  want  of  uniform- 
ity is  suspected,  a  piece  of  5  feet  in  length  may  be  taken  from  the  other 
end  of  the  ring. 

Fourthly. — Every  ring  will  be  subjected  to  a  bending  test  by  cutting 
off  from  each  ring  a  piece  of  wire  one  foot  long,  and  coiling  it  closely  and 
continuously  around  a  rod  one-half  inch  in  diameter,  when,  if  it  breaks,  it 
will  be  rejected. 

GENERAL  REMARKS  ON  TESTING. 

At  the  first  glance  these  tests  may  seem  rather  onerous  and  exacting 
in  their  requirements,  but  they  will  not  appear  so  to  a  manufacturer  who 
has  been  in  the  habit  of  having  his  work  tested,  and  is  desirous  of  not 
only  maintaining,  but  adding  to  an  established  reputation.  The  spirit  of 
these  tests  does  not  consist  so  mucli  in  the  rejection  of  a  random  ring 
here  aud  there,  as  it  does  in  impressing  on  the  operatives,  and  all  con- 
cerned, the  assurance  that  no  bad  work  can  possibly  pass  the  inspection. 
It  is  only  when  this  has  become  a  certainty  that  we  can  rely  upon  a 
steady  and  uniform  character  in  the  quality  of  the  wire. 

Nothing  is  more  common,  for  instance,  than  to  lose  the  whole  of  the 
day's  work  by  reason  of  a  wrong  temperature  in  the  galvanizing  bath,  or  to 
spoil  tons  upon  tons,  by  faulty  tempering,  all  of  which  would  be  pushed 
for  acceptance  if  there  were  no  daily  inspections  going  on.  This  is  usu- 
ally the  case  towards  the  end  of  a  contract  when  the  final  deliveries  are 
wanted  in  a  hurry.  Finally,  it  may  be  said  that  in  these  tests  no  unat- 
tainable standard  has  been  set  up,  but  the  requirements  are  such  as  can 
be  filled  with  ease  and  certainty  by  many  manufacturers. 

INSPECTORS  AND  MACHINES. 

12.  The  inspection  will  be  performed  by  the  authorized  assistants  of  the 
Engineer,  or  by  specially  appointed  inspectors.  They  are  paid  by  the  Trus- 
tees. The  testing  machines,  however,  as  well  as  all  manual  labor  required 
in  handling  the  wire,  preparing  the  specimens,  and  the  actual  work  of  test- 
ing, must  be  furnished  by  the  manufacturer.  The  testing  machines  will 
probably  not  be  more  than  three  in  number,  and  this  will  be  comparative- 
ly a  small  expense,  as  their  capacity  need  not  exceed  two  gross  tons. 
After  the  system  of  inspection  has  once  been  thoroughly  organized  it 
will  be  found  that  the  expense  connected  with  it  forms  an  exceedingly 
small  percentage  of  the  total  cost  of  the  wire.  Proper  room  and  facilities 
must  be  furnished  for  this  work. 

In  case  of  any  dispute  arising  between  the  inspector  and  the  manufac- 
turer, the  Engineer  is  to  be  the  sole  arbiter. 

SIZE  OF  RINGS. 

13.  Long  rings  are  indispensable  The  weight  must  average  60  lbs. 
None  weighing  less  than  50  lbs.  will  be  received,  and  they  may  be  as 
much  heavier  as  can  be  made,  provided  the  ends  are  of  uniform  diame- 


77 


ter.  With  the  recent  improvements  in  rolling  machinery,  loDg  rings  have 
become  the  rule  instead  of  the  exception,  as  was  formerly  the  case.  By 
having  long  rings  the  time  and  labor  of  splicing  the  wire  is  reduced  pro- 
portionably.  The  splice  being  the  weakest  spot  we  increase  the  average 
strength  by  having  long  rings,  and  by  reducing  their  number.  The  wire 
is,  besides,  of  so  coarse  a  size,  that  even  a  60  lb.  ring  will  not  much  more 
than  reach  half-way  across  the  main  span.  Hence,  at  the  best,  the  rela- 
tive number  of  splices  will  be  far  greater  than  in  any  previous  cable. 
The  rings  must  be  of  such  a  diameter  as  not  to  give  the  wire  a  perma- 
nent bend.  The  inspectors  will  also  pay  particular  attention  that  both 
ends  of  these  long  rings  have  the  same  uniform  gauge  and  thickness — as 
wire  of  uneven  weight  cannot  be  properly  regulated  in  making  the 
strands.    This  examination  will  be  made  before  the  wire  is  galvanized. 

Only  one  nipper  mark  can  be  permitted  on  the  end  of  a  ring,  and  that 
at  a  distance  not  exceeding  5  in.  from  the  end. 

When  the  end  of  the  wire  is  pulled  through  the  draw  plate  for  the 
purpose  of  fastening  it  to  the  block,  it  must  be  done  at  one  operation,  and 
not  by  successive  applications  of  the  nippers,  as  is  usually  done. 

The  dents  caused  by  the  nipper  jaws  injure  steel  wire  very  materially, 
and  hence  not  more  than  one  is  allowed. 

GENERAL  REMARKS  AND  TIME  OF  DELIVERY. 

14.  Tt  is  required  that  the  manufacturer  will  at  once,  upon  the  giving 
out  of  this  contract,  prepare  to  make  and  deliver  about  50  tons  of  this 
wire.  This  is  necessary,  in  order  that  the  contractor  can  make  the  nec- 
essary preparations  in  the  various  processes  of  the  manufacture,  so  as  to 
be  able  to  turn  out  the  regular  quantities  in  the  time  specified.  In  these 
preliminary  50  tons  ample  time  is  given  to  overcome  all  defects  which 
may  exist  in  the  beginning,  and  also  to  come  to  a  perfect  understanding 
with  the  inspectors  as  regards  any  doubtful  questions  which  may  arise 
in  regard  to  the  modes  of  testing  or  the  standards  required. 

The  regular  deliveries  of  wire  will  commence  February  1st,  1877.  The 
amount  of  these  monthly  deliveries  must  be  no  less  than  150  tons,  and  in 
case  it  should  be  found  that  the  cable-making  proceeds  faster  than  at 
present  anticipated,  tho  manufacturer  must  increase  this  amount  to  200 
tons,  upon  being  duly  notified  by  the  Engineer,  at  least  two  months  in 
advance. 

15.  Inasmuch  as  the  precise  quantity  of  wire  in  these  cables  cannot  be 
ascertained  until  some  of  the  strands  are  actually  made,  and  all  the  wire 
composing  a  strand  has  been  weighed,  the  Engineer  reserves  the  right  to 
increase  or  diminish  the  quantity  of  wire  called  for  in  this  contract  by  the 
amount  of  200  tons,  the  same  to  be  furnished  at  the  regular  contract  price, 
provided  he  gives  notice  to  that  effect  three  months  before  the  completion 
of  the  contract. 

16.  All  parties  who  expect  to  bid  on  this  wire  are  requested  to  send 
samples  in  accordance  with  these  specifications,  the  samples  to  weigh  no 


78 


ess  than  100  lbs.,  and  to  contain  two  rings.  Foreign  parties  may 'con- 
sign them  to  E.  L.  Alexander,  117  Liberty  street,  New  York,  marked 
Bridge  wire. 

17.  The  wire  intended  for  shipment  should  be  properly  packed,  and  so 
wrapped  as  to  avoid  injury  to  the  galvanizing. 

MANNER  OP  BID. 

18.  Bids  will  be  received  at  so  much  per  lb.,  gold,  for  the  whole 
amount  delivered  at  the  Brooklyn  Tower.  It  is  deemed  best  to  place  the 
bids  on  a  gold  basis,  in  order  to  eliminate  the  question  of  the  probable 
changes  in  the  value  of  the  currency  for  the  period  of  time  over  which  this 
contract  will  extend.  It  would  be  impossible  to  foresee  these  changes  ac- 
curately, and  the  margin  that  the  contractor  would  be  forced  to  allow 
himself  would,  of  necessity,  be  against  the  interests  of  the  Bridge.  The 
duties  on  both  the  steel  rod  and  on  the  finished  wire  are  payable  in  gold. 
The  duties  on  this  kind  of  wire  are  at  present  1\  cents  per  lb.,  and  20  per 
cent,  ad  valorem.  The  cost  of  lighterage  from  the  foreign  steamship 
wharves  on  the  North  River,  to  the  wharf  at  the  Brooklyn  Tower,  is  about 
65  cents  per  ton  in  currency.  Ocean  freights  of  course  differ,  according 
to  shipping  port. 

No  bid  will  be  received  which  does  not  include  the  duties. 

BONDS. 

19.  In  order  to  insure  the  complete  and  satisfactory  performance  of  the 
requirements  laid  down  in  these  specifications,  the  successful  bidder  shall 
give  good  and  sufficient  bonds  to  the  amount  of  $50,000 — gold.  This 
will  take  the  place  of  the  back  percentage  which  has  usually  been  retain- 
ed in  other  contracts. 

PAYMENT. 

20.  The  Trustees  will  pay  on  the  10th  of  every  month,  in  full,  in  gold, 
for  all  the  wire  delivered  during  the  previous  month. 

21.  It  is  furthermore  to  be  understood  by  the  successful  bidder,  that 
if  at  any  time  during  the  performance  of  his  contract  he  shall  fail  to  com- 
ply with  the  terms  of  these  specifications  and  produce  a  wire  which  does 
not  come  up  to  the  test  required,  and  has  to  be  constantly  rejected  by  the 
inspectors,  or  if  he  is  manifestly  unable  to  produce  the  necessary  quanti- 
ty in  the  required  time,  the  Engineer  of  the  Trustees  shall  duly  and  offi- 
cially notify  him,  in  writing,  of  this  neglect  and  failure  on  his  part,  and  if, 
notwithstanding  this  notice,  the  required  improvement  is  not  made,  then 
the  Trustees  may  declare  his  contract  null  and  void,  and  shall  have  the 
right  to  contract  with  other  parties  at  either  the  same  price  or  some  other 
price,  and  if  loss  should  occur  to  the  Trustees  by  this  transaction,  that 
they  then  have  the  right  to  take  the  whole  or  part  of  the  aforementioned 
bonds  of  $50,000,  to  cover  themselves  from  such  loss. 

22.  On  the  other  hand,  if  from  some  unforeseen  circumstance,  which  at 


70 


present  the  Trustees'  have  no  knowledge  of,  they  should  be  compelled  to 
suspend  operations  on  the  work,  they  reserve  the  right  to  notify  the  con- 
tractor to  suspend  the  delivery  of  the  wire,  either  for  a  fixed  or  an  indefin- 
ite period,  provided  they  serve  him  with  a  notice  to  that  effect,  at  least 
three  months  before  such  suspension  ;  and  the  fact  of  having  given  such 
a  notice  is  to  be  a  bar  against  any  claim  for  damages  arising  from  the  sus- 
pension of  this  contract. 

23.  The  Trustees  reserve  the  right  to  reject  any  or  all  the  bids  that 
may  be  offered,  or  to  divide  the  contract  into  not  more  than  four  portions, 
in  case  it  should  prove  to  their  interest  to  do  so. 

24.  Bids  must  be  addressed  to  the  Trustees  of  the  New  York  and 
Brooklyn  Bridge,  No.  21  Water  street,  Brooklyn,  N.  Y.,  and  endorsed 
"  Proposals  for  Cable  Wire." 

W.  A.  ROEBLING, 
Engineer  New  York  and  Brooklyn  Bridge. 

INSTRUCTIONS  TO  BIDDERS. 

1.  All  proposals  must  be  made  upon  the  form  accompanying  these 
specifications,  all  the  blanks  of  which  must  be  filled. 

2.  The  full  name  and  address  of  the  parties  bidding  shall  be  given,  and 
a  seal  attached  to  all  signatures. 

3.  The  guarantee  attached  to  the  bid  must  be  signed  by  two  responsi- 
ble guarantors,  known  to  be  good  and  sufficient  by  these  Trustees,  or 
certified  to  be  such  by  some  responsible  person  so  known. 

4.  Parties  making  bids  are  understood  as  accepting  all  of  the  terms 
and  conditions  contained  in  the  specifications,  the  specifications  being  con- 
sidered a  part  of  the  agreement. 

5.  The  bidder  must  be  a  manufacturer  of  steel  wire,  and  must  give 
satisfactory  evidence  of  his  ability  to  furnish  the  quantity  and  quality 
of  wire  required,  within  the  specified  time. 

PROPOSAL. 

1876 

,  the  subscriber  ,  do  hereby  propose  to  make  and  furnish  all 
the  Steel  Wire  called  for  in  these  specifications,  in  accordance  with  all 
the  requirements  therein  set  forth,  for  the  sum  of 

cents  per  pound,  gold,  payable  in  monthly  installments,  upon  the  terms 
and  conditions  mentioned  in  said  specifications. 

further  agree  that  upon  being  notified  that  bid  is  ac- 

cepted, and  also  furnished  with  the  form  of  contract,  will,  within 

ten  days  thereafter,  execute  said  contract  with  the  Trustees  of  the  New 
York  and  Brooklyn  Bridge,  with  good  and  approved  securities,  to  furnish 
said  wire  upon  the  terms  and  conditions  set  forth  In  these  specifications, 
the  same  to  be  embodied  in  said  contract. 

To  all  of  which  hereby  agree. 

Witnese,  [L.  S.] 


80 


GUARANTEE. 

The  undersigned,  of 
hereby  guarantee  that  in  case  the  foregoing  bid  of 
be  accepted,       will,  witbin 
ten  days  after  receipt  of  contract  and  notice  of  tbe  acceptance  of  said  bid, 
execute  the  contract  with  good  and  sufficient  sureties  ;  and  in  case  said 
shall  fail  to  enter  into  contract  as  aforesaid,  we  guarantee 
to  pay  over  into  the  hands  of  the  Trustees  of  said  Bridge  the  sura  of  ten 
thousand  dollars,  gold. 

Signed, 

Date. 
Witness. 


II. 

WIRE  TESTS. 


REPORT  OF  THE  CHIEF  ENGINEER  ON  THE  TESTS  OF 
THE  SAMPLES  OF  WIRE. 

No.  33  W.  50th  street,  December  18,  1876. 

Hon.  Henry  C.  Murphy,  President  of  the  Board  of  Trustees  of  the 
New  York  and  Brooklyn  Bridge. 

Dear  Sir  : 

In  compliance  with  your  request  of  the  16th  inst.,  I  present  the 
following  report  on  the  tests  for  cable  wire. 

The  samples  were  presented  and  tested  in  conformity  with  para- 
graph 16  of  the  specifications,  which  says  : 

"  All  parties  who  expect  to  bid  on  this  wire  are  requested  to  send 
samples  in  accordance  with  these  specifications,  the  samples  to  weigh 
no  less  than  100  lbs.,  and  to  contain  two  rings." 

The  only  object  of  this  section  was  first,  to  satisfy  myself  that  each 
bidder  could  make  such  wire  as  was  called  for  in  the  specifications, 
and  secondly,  that  each  bidder  should  satisfy  himself  that  such  wire 
could  be  easily  made,  and  involved  no  impossible  demands. 

The  testing  of  these  samples  was  performed  by  Col.  Paine  and  Mr. 
Martin. 

Details  are  given  on  a  sheet  accompanying  this  report  (marked  A). 
They  comprised  samples  from  the  following  parties  :  J.  Lloyd 
Haigh,  Cleveland  Rolling  Mill  Company,  Washburn  &  Moen,  John 
A.  Roebling's  Sons  Co.,  Johnson  &  Nephew,  Sulzbacher,  Hymen, 
Wolff  &  Co.,  Carey  &  Moen,  and  W.  T.  Henly  &  Co. 

A  general  glance  over  the  results  shows  the  gratifying  fact  that 
pretty  much  every  bidder  has  been  able  to  reach  our  requirements, 
and  that  if  every  one  has  not  reached  perfection  on  every  test, 
they  have  at  least  shown  that  on  further  trial  the  results  can  no 
doubt  be  obtained. 

6 


82 


Where  all  have  so  nearly  approached  excellence  it  would  per- 
haps be  wrong  to  institute  any  invidious  comparisons  among  them, 
but  the  facts  certainly  show,  that  Richard  Johnson's  Nephew 
stands  at  the  head  of  the  list,  and  Mr.  Henly  at  the  foot,  but  even 
his  wire  is  not  far  out  of  the  way  in  some  respects,  and  the  other 
bidders  range  in  various  degrees  between  these  two  limits. 

The  appearance  of  the  various  specimens  present  marked  con- 
trasts. Many  show  signs  of  having  been  prepared  with  the  great- 
est care  in  getting  them  up,  and  of  being  the  product  of  laborious 
selection  and  rejections.  Others  again  show  signs  of  carelessness 
and  indifference,  as  if  they  had  been  pulled  at  random  out  of  a 
pile,  and  nothing  in  this  world  were  easier  than  to  make  this 
wire. 

There  are  a  number  of  facts  attending  these  samples  which  require 
comment  on  my  part.  I  possess  no  information,  either  written  or 
verbal,  except  in  a  few  cases,  as  to  the  stock  or  material  of  which 
these  specimens  are  composed,  that  is,  whether  they  are  made  of 
crucible  cast-steel,  Bessemer  or  Open  Hearth  steel,  or  by  some  secret 
process.  Neither  do  I  know  whether  the  bidder  in  his  written  tender 
states  the  material  from  which  his  samples  were  made,  or  from 
which  he  intends  to  make  the  cable-wire ;  of  one  fact,  however,  I 
am  certain,  that  I  have  no  evidence,  and  in  the  nature  of  the  case 
can  have  no  evidence  that  the  successful  bidder  will  make  his  cable- 
wire  of  precisely  the  same  material  as  shown  by  the  samples  here 
presented.  It  would  be  very  unwise  to  accept  two  specially  pre- 
pared rings,  as  an  absolute  guarantee  of  the  perfection  of  6,000,000 
pounds.  Fortunately  this  makes  no  difference  to  me,  as  no  wire  can 
reach  the  Bridge  that  has  not  satisfactorily  passed  through  the  inspec- 
tor's hands  before  leaving  the  manufactory. 

I  desire  to  extend  my  thanks  to  all  who  have  presented  the  sam- 
ples for  the  zealous  alacrity  with  which  they  have  responded  to  my 
request.  The  amount  of  labor  entailed  on  each  in  making  experi- 
ments in  various  grades  of  steel  must  have  been  very  great,  and  the 
results  have  been  most  valuable. 

Furthermore,  modes  of  treatment  have  been  arrived  at,  which 
obviated  the  use  of  expensive  patent  processes,  and  cheaper  grades 
of  steel  have  been  manipulated  in  such  a  manner  as  almost  to  equal 
the  most  expensive  ones.  All  of  this,  together  with  the  close  compe- 
tition caused  by  the  great  depression  of  business,  must  have  the 
effect  to  materially  diminish  the  cost  of  the  wire. 

The  results  of  these  tests  show  an  average  modulus  of  elasticity  of 
about  1,000,000  in  excess  of  that  called  for  in  the  specifications. 
The  latter  is  evidently  placed  too  low  by  that  amount.  This  differ- 
ence was  owing  to  the  fact  that  the  large  number  of  samples  tested 
prior  to  writing  out  the  specifications,  were  almost  wholly  of  curved 
wire,  which  showed  no  true'modulus  or  limit  of  elasticity. 


S3 


I  will  close  this  report  by  a  cursory  review  of  the  tests  of  the  sam- 
ples submitted : 

Mr.  J.  Lloyd  Haigh  presented  several  samples  of  very  good  wire, 
apparently  cast-steel,  of  three  different  stocks.  The  tensile  strength 
exceeding  the  requirements,  the  elongation  very  good,  the  elastic 
limit  up  to  the  mark,  the  modulus  of  elasticity  admissible.  This 
wire  is  very  straight,  galvanizing  smooth,  the  polish,  though  of  no 
advantage,  adds  to  the  appearance  of  the  wire.  Some  of  his  samples 
fully  reached  the  requirements  of  the  bendiug  test — others  did  not. 
The  diameter  at  the  point  of  fracture  was  usually  too  large. 

The  Cleveland  Rolling  Mill  Co.  presented  two  rings  of  very 
good  wire,  we  do  not  know  of  what  stock,  of  high  degree  of  strength 
and  of  requisite  ultimate  stretch,  with  required  limit  of  elasticity  in 
one  ring  and  a  deficiency  in  the  other,  owing  to  its  not  being  as 
straight.  Modulus,  high  and  variable.  The  diameter  at  the  point  of 
fracture  was  good,  as  was  also  the  bending  test. 

The  want  of  regularity  in  the  galvanizing  has  been  explained,  and 
attributed  to  their  not  being  fully  prepared  to  galvanize  wire. 

The  Washburn  &  Moen  Manufacturing  Co.  presented  two  rings 
of  good  wire,  stock  unknown,  of  a  high  degree  of  strength,  but 
somewhat  deficient  in  stretch.  A  small,  permanent  elongation  ap- 
pears, owing  to  the  wire  not  being  quite  straight. 

The  diameter  at  the  point  of  fracture  is  considerably  within  the 
limit  mentioned,  and  the  wire  stood  the  bending  test  very  well.  The 
galvanizing  was  good. 

The  John  A.  Roebling's  Sons  Co.  presented  two  rings  of  cast- 
steel  wire,  and  two  rings  of  Bessemer  stock. 

The  short  tests  of  the  cast-steel  wire  indicated  a  high  tensile 
strength,  while  the  long  tests  fell  below  the  requirements.  The 
elongation  was  deficient  in  the  long  tests.  The  limit  of  elasticity  is 
high  and  variable,  and  the  bending  tests  not  satisfactory ;  galvaniz- 
ing, rough. 

One  ring  of  the  Bessemer  wire  was  very  good.  It  was  high  in 
strength  and  stretch,  coming  within  the  requirements  as  to  its  elastic 
limits,  and  favorable  as  to  modulus  and  decreased  section  at  fracture, 
and  stood  the  bending  tests  very  well.  The  galvanizing  a  little  uneven. 
The  other  ring  of  the  Bessemer  wire  was  uneven.  One  short  test 
made  at  one  end  came  up  to  all  the  requirements,  except  the  elastic 
limit,  and  fell  below  in  this  because  it  had  not  been  properly  straight- 
ened. Tests  of  the  other  end  of  the  same  wire  indicated  a  want  of 
strength.  It  Bhowej  favorable  results  as  to  modulus  of  elasticity 
and  diminution  of  section  at  breaking  point.  The  bending  test  was 
not  as  good  as  the  previous  piece  ;  galvanizing,  rough. 

Messrs.  Richard  Johnson  and  Nephew  furnished  two  qualities  of 
very  superior  wire.    One  quality  was  represented  by  a  single  ring 


84 


weighing  114  pounds,  with  the  great  tensile  strength  of  about  200,000 
pounds  per  square  inch,  with  a  large  ultimate  elongation.  The  mod- 
ulus and  limit  of  elasticity  were  unobtainable,  as  the  wire  was  made 
on  the  usual  two  feet  drum  and  had  not  been  straightened.  It  had  a 
curve  about  five  feet  diameter.  The  bending  and  galvanizing  was 
passable,  and  the  diminution  of  section  good. 

The  other  quality  had  a  strength  somewhat  above  the  requirements, 
with  an  unusual  amount  of  stretch  and  diminution  of  section.  The 
elastic  limit  and  modulus  were  equally  unsatisfactory  with  the  other 
specimen.  The  bending  test  was  satisfactory,  the  galvanizing  passa- 
ble. If  this  wire  had  been  galvanized  straight  it  would  no  doubt 
have  met  all  the  requirements. 

Messrs.  Sttlzbacher,  Hyman,  Wolff  &  Co.  sent  two  rings  of  ex- 
cellent steel  wire,  having  a  high  degree  of  strength.  One  fulfilled 
all  that  we  require,  but  the  other  failed  somewhat  in  stretch, 
diminution  of  section  at  point  of  fracture,  and  on  the  bending 
test.  This  wire  was  quite  straight,  and  exhibited  a  high  limit  of  elas- 
ticity.    The  modulus  of  elasticity  was  somewhat  uneven  and  high. 

Messrs.  Cart  &  Moen  presented  four  rings  of  wire,  two  of 
which  were  very  high  in  tensile  strength,  coming  up  to  the  required 
elongation,  except  in  one  test,  but  failing  in  regard  to  limit  of  elastic- 
ity, on  account  of  some  short  bends  ;  the  wire  being  generally 
straight.  The  modulus  of  elasticity  was  quite  high,  the  section  at 
point  of  fracture  large,  the  bending  test  wTas  satisfactory,  and  the 
galvanizing  good. 

The  other  two  rings  were  very  uneven  as  regards  strength  and 
stretch,  some  of  the  tests  going  above,  and  others  falling  below  the 
requirements.  The  limit  of  elasticity  and  modulus  were  also  uneven, 
as  was  also  the  diameter  at  the  fracture.  The  bending  tests  were 
usuall}'  good,  and  the  galvanizing  well  done. 

The  irregularities  are  largely  attributable  to  short  bends  found  in 
parts  of  the  wire,  while  other  parts  were  straight  and  even,  owing 
to  imperfect  arrangements  for  galvanizing  the  wire  straight. 

Messrs.  Hexley  &  Co.  furnished  two  rings  of  wire  which  failed 
in  strength,  stretch,  and  so  many  other  particulars,  that  it  is  not 
deemed  necessary  to  make  further  reference  to  them. 
^  The  conclusions  to  be  arrived  at  in  this  whole  matter  are  simply 
these.  If  our  cables  are  to  be  made  of  the  strongest  obtainable  wire, 
regardless  of  cost,  we  must  take  some  of  the  finer  qualities  of  cast- 
steel,  of  which  some  samples  have  been  presented  ;  but  if  we  make 
our  cables  of  wire  of  the  strength  and  quality  called  for  in  the  speci- 
fications, combined  with  the  minimum  cost,  then  our  course  is  clear  ; 
because  a  few  of  the  samples  presented  are  made  of  the  medium 
grades  of  steel,  which  have  essentially  reached  all  the  necessary 
requirements. 


85 


The  duty  of  the  Trustees  is  to  buy  a  certain  fixed  quality  for  the 
least  money. 

Respectfully  submitted, 

W.  A.  ROEBLING, 

Chief  Engineer. 

I  desire  my  letter  of  the  15th  inst.,  to  the  President  of  the  Board 
of  Trustees,  to  be  appended  to  this  Report,  as  the  views  I  then  ex- 
pressed are  the  same  as  1  now  hold  on  this  question. 

W.  A.  R. 


(The  following  is  the  letter  referred  to  in  the  preceding  postscript.) 

No.  33  W.  50th  street,  •» 
December  15,  1876.  j 

Hon.  H.  C.  Murphy,  President  Board  of  Trustees  New  York  and 
Brooklyn  Bridge. 

Dear  Sir  : 

As  my  opinion  will  probably  be  asked  on  the  wire  business  before 
the  letting  of  the  contract,  I  should  like  to  give  it  before  my  mind 
can  be  biased  by  a  knowledge  of  the  bids,  of  which  I  am  now  in  total 
ignorance. 

I  would  premise  by  remarking  that  an  undue  importance  seems  to 
have  been  attached  to  the  testing  of  the  samples  accompanying  the 
bids.  How  it  arose  I  am  at  a  loss  to  imagine.  The  only  reference 
thereto  is  contained  in  paragraph  10  of  the  specifications,  which  says  : 
'*  All  parties  who  expect  to  bid  on  this  wire  are  requested  to  send 
samples  in  accordance  with  these  specifications,"  etc. 

There  is  nothing  mandatory  or  obligatory  in  this.  No  intimation 
that  if  the  sample  was  not  sent  the  bid  would  be  thrown  out.  This 
is  as  it  should  be,  because  we  have  no  positive  assurance  that  any 
bidder  will  send  all  the  wire  exactly  like  the  samples  he  sent.  If  one 
man's  samples  were  too  good  he  would  be  sure  to  reduce  his  stan- 
dard, provided  he  got  the  contract,  and  another  man,  whose  wire  fell 
short  of  the  standard,  would  have  to  make  his  wire  come  up  to  the 
mark  before  any  could  be  accepted. 

When  I  wrote  this  section  No.  16,  I  had  two  objects  in  view  ;  one 
was  that  each  bidder  should,  by  actual  trial,  ascertain  for  himself 
what  would  be  required  of  him,  so  that  he  would  put  in  a  bid  with  a 
full  understanding  of  the  subject,  and  could  raise  no  plea  of  igno- 
rance on  this  point  or  that  ;  the  other  object  was,  that  each  man 
should  convince  himself  that  there  was  no  unjust  or  arbitrary  exac- 
tions in  these  specifications  which  it  would  be  impossible  to  fulfill. 

In  paragraph  14  of  the  specifications,  I  go  still  further,  and  give 


86 


the  manufacturer  two  mouths  in  which  to  perfect  the  manufacture 
of  this  cable-wire. 

I  know  that  nothing  can  be  done  perfectly  at  the  first  trial ;  I  also 
know  that  each  day  brings  its  little  quota  of  experiences,  which  with 
honest  intentions,  will  lead  to  perfection  after  a  while. 

If  I  am  asked  point  blank,  I  shall  have  to  say  the  wire  of  Richard 
Johnson  &  Nephew  was  by  far  the  best  of  all  the  samples  sent  with 
the  bids,  notwithstanding  the  fact  that  it  was  not  straightened. 

Placing  his  at  the  head  of  the  list,  the  rest  range  down  with  all 
sorts  of  perfections  and  imperfections. 

When  I  drafted  these  specifications  in  August,  of  1875,  I  knew  the 
contract  was  to  be  given  to  the  lowest  bidder,  without  regard  to  the 
quality  of  the  wire,  and  it  was  my  duty  to  guard  these  specifications 
with  tests  and  restrictions,  which,  if  faithfully  followed  out.  would 
fully  warrant  the  Trustees  in  giving  the  contract  to  the  lowest 
bidder. 

The  surety  clause  of  $50,000  is,  of  itself,  a  powerful  inducement 
to  make  the  contractor  come  up  to  the  mark.  As  for  the  tests  them- 
selves, they  have  been  scrutinized  by  interested  parties,  who  all  bear 
testimony  as  to  their  searching  character. 

We  know  that  the  wire  is  to  be  tested  at  the  manufactory,  and  that 
none  can  arrive  at  the  Bridge  unless  it  has  passed  through  the  hands 
of  an  inspector. 

Of  all  known  materials,  wire  possesses  a  shape  most  susceptible  of 
being  tested  in  every  direction.  If  necessary,  a  wbole  mile  of  it 
could  be  tested  for  its  elasticity,  throughout  every  foot  of  its  length, 
without  injuring  it  in  the  slightest  degree.  It  is  not  like  a  huge 
casting.  wilich  may  be  full  of  hidden  flaws,  or  like  a  big  gun  which 
bursts  at  the*  first  discharge. 

Even  in  the  process  of  strand  making,  every  wire  is  strained  from 
anchorage  to  anchorage  with  a  load  of  400  pounds,  which  is  only  a 
few  hundred  pounds  less  than  the  permanent  strain  caused  by  the 
weight  of  the  whole  bridge.  What  more  can  be  asked  than  this,  I 
fail  to  see. 

Very  respectfully  vours, 

W.  A.  ROEBLING. 


REPORT  OF  ASSISTANTS  MARTIN  AND  PAINE  ON  THE 
RESULT  OF  THE  TESTS. 

Pier  29,  East  River,  > 
New  York,  Dec.  16,  1876.  j" 

Col.  W.  A.  Roebling, 

Chief  Engineer  New  York  and  Brooklyn  Bridge. 

Dear  Sir  : 

We  herewith  present  the  results  of  tests  made  by  us  in  accordance 
with  your  instructions,  of  the  samples  of  wire  furnished  by  parties 


TABULAR  STATEMENT, 

Giving  the  rcxults  of  trstx  imvh  of  sum  pits  of  git/vmn'sed  xtxl  wire,  Kent  with  the  bids  for  furnishing  the 
cable  wire  for  the  East  River  Bridge. 

EXPIiAlTATIOH    OE    TIP!  E  TABLE. 


acreage  of  strain 


I  In-  «■  iitlil  "I  ■  mil 


2  3  4  5  6  7 


9  10  11  12 


Bending  Test. 
Turns  -  Dlam. 

WRIilllT 

Lbs'.  ' 

straight. 

' 

StralgM. 

Sliaiitht. 

12  tect  Diameter 

..  ,)    ..   i,  .. 

..    B      ..     B  .. 

Contll  is  H  in.    10  feel  Diameter. 

L'nil  li  .V  C_100— End  A  — 

88 

3.i)>r. 

1  996 

|«. 

.0440 

.00001 

139 

Nearly  straight. 

Coil  B  A  C--2"ll—  End  A— 

3!s46 

Straight. 

29.94S.890 

.159 

09 

1 

.0000?+ 
0+ 

3ii.2ii7.I5I 
T'i!> 

.154 
.103 

NVaily  straight. 

; 

.l|.,23l.9.".l 

■--.l^.i.r.i 

29.105.023 

Coil  1-Kii.i  \-lV.i. 

. 00001 t 

'  1 

0  1  ! 

29.749.408 
•.".I.'.I52.II2!I 

12*  It.  Diameter. 

3    ••  is 
..      ..  B 

'.'.'.'.'.']   s.'wii  i.'!-.!i!t3 

  3,275  150,371 

.00001 

'  13- 

.00001 

■.".1.749,1111 

■."j,.'5;.Mi 

29,432.1)10 

S'  It  Diameter   '  " 

a 

End  A-Wire  1."  

"    B       "  1  

.149 

1 

o 

!l29 
134 

53 

o 

Continuous  a  in. 

Bend.. 

.00001 

'.imi 

49X 

173,091,  |  100  " 

'h'idii 
.0234 

.ooooS 

m 

Bundle  1— End  A — Wire 

1  ••  B  •• 

2  "    B  ■• 

3,305 
3.305 

own 

5  II.  Diameter. 

S7 


who  have  presented  proposals  to  furnish  the  Steel  Cable-Wire 
required  for  the  construction  of  the  East  River  Bridge,  as  called  for 
by  the  published  specifications. 

We  have  endeavored  to  make  the  tabulated  results  so  full  and  com- 
plete as  to  obviate  the  necessity  of  writing  out  a  long  detailed  state- 
ment. 

All  of  the  parties  proposing  to  furnish  this  wire  were  present,  in 
person  or  by  representatives,  during  all  or  a  portion  of  the  time 
employed  in  making  these  tests,  excepting  Mr.  Henley. 

A  few  tests  of  Mr.  Haigh's  wire  were  made  before  the  general 
invitation  to  all  the  bidders  was  given.  The  results  of  these  tests 
are  submitted  on  a  separate  sheet,*  as  another  complete  set  of  tests 
of  his  wire  were  made  in  the  presence  of  the  other  bidders,  and  are 
included  in  the  tabulated  results. 

All  of  which  is  respectfully  submitted. 

C.  C.  MARTIN, 
W.  EL  PAINE. 


Test  of  Steel  Wire  received  from  the  Chrome  Steel  Company. 


Designation. 

Feet,  per  lb. 

Ultimat 
Per  Wire. 

s  Strain 

Per  Square  In. 
Steel  Section. 

*i 

—  T. 

Total 
Stretch 
in  dec.  of 
Length. 

lbs. 

lbs. 

ft. 

Wire  1  

10.97 

4,350 

160,632 
160,208 

5 

.032 

14  2 

10.S2 

4,400 

5 

.025 

"  3  

10.S3 

4,420 

161,146 

5 

.034 

Coil  X,  Wire  1 . 

11.77 

4,050 

160.472 

100 

.0106 

"  Y,     "  1. 

12.17 

4,155 

170,150 

100 

.0190 

"  Z,     "  1. 

11.87 

3,770 

150,657 

100 

.0155 

No  reliable  modulus  or  limit  of  elasticity  could  be  obtained  on 
account  of  curve  in  wire. 
Tests  made  March,  187G. 

C.  C.  MARTIN, 
W.  H.  PAINE. 

A  arista  n  t  En  gin  eers. 

*  Not  printed. 


Note.— From  information  subsequently  obtained,  the  character  of  the  steel 
from  which  the  various  samples  of  wire  tested  were  made,  is  believed  to  be  as 
follows : 

J.  Lloyd  Haigrh— English  crucible  cast-steel. 

Cleveland  Rolling  Mill— Open  Hearth  steel,  of  their  own  manufacture. 
Washburn  At  Moen— English  crucible  cast-steel. 

Sulzbacher,  Hymen,  Wolff  &  Co.— Sample  marked  B  and  C  100:  Krupp's  Besse- 
mer steel.   Sample  marked  B  and  C  200  :  Krupp's  cast-steel. 

John  A.  Roebling's  Sons  Co.— Bundle  O:  Crucible  cast-steel.  Bundle  R: 
American  Bessemer  steel. 

Johnson  &  Nephew— English  crucible  cast-steel. 

Carey  &  Moen— English  crucible  cast-steel. 

Henley— English  crucible  cast-steel.  (?) 

Chrome  Steel  Co.— Crucible  cast-steel,  of  their  own  manufacture. 


III. 

REPORTS 

OF 

ASSISTANT  ENGINEERS 

AND 

MASTER  MECHANIC. 


GENERAL  REPORT.  1875—1876. 

Col.  W.  A.  Roebling, 

Chief  Engineer  of  the  New  York  and  Brooklyn  Bridge. 

Dear  Sir: 

As  no  reports  from  the  Engineering  Department  were  printed  last  year, 
I  herewith  submit  a  summary  of  the  general  progress  of  the  work  on  the 
bridge  for  the  past  two  years. 

Beginning  at  the  Brooklyn  Anchorage,  as  first  in  order,  I  would  state 
that  this  structure  was  practically  finished  a  year  ago,  so  far  as  it  can  be 
until  the  cables  have  been  made.  The  work  done  this  year  has  consisted 
in  cleaning  out  and  pointing  the  joints  of  the  arches;  trimming  the  cor- 
ners and  arches,  and  cutting  a  "  wash"  on  the  offset.  The  cost,  including 
the  amount  paid  for  274  yards  of  limestone  stored  for  future  use,  has  been 
$7,486.31. 

During  the  season  101,909  pounds  of  anchor  bars  and  pins  have  been 
received  and  placed  in  position  at  a  cost,  including  labor,  of  $7,023.45. 

The  final  estimate  on  the  chains  and  plates  for  both  anchorages  shows 
a  saving  on  the  whole  over  the  estimate  of  last  year  of  $1,067.70. 

The  large  engine  and  boiler  that  were  used  for  the  main  hoist  in  build- 
ing the  Brooklyn  Tower,  have  been  removed  to  the  anchorage  and  placed 
in  position  for  running  the  cable-making  machinery,  which  machinery 
has  also  been  put  in  place  during  the  year. 


89 


This  work  has  been  in  charge  of  Assistant  Engineer  Mr.  G.  W.  Mc- 
Nulty.  Reference  is  here  made  to  his  report  for  detailed  information 
concerning  the  work  done  in  1875.  He  has  had  entire  charge  of  that 
portion  of  the  Anchorage  which  is  above  ground,  and  has  done  the  work 
rapidly  and  well,  especially  when  the  many  hindrances  due  to  slow  de- 
liveries of  stone  and  other  materials  are  considered. 

The  engines,  tools,  derricks,  supplies  and  materials,  aside  from  cable- 
making  machinery,  but  including  present  value  of  railroad,  stored  at  the 
Anchorage  yard,  inventory  at  $15,875. 

No  work  was  done  at  the  Brooklyn  Tower  and  yard  during  1876,  ex- 
cept in  connection  with  preparations  for  cable-makiug.  The  report 
of  Assistant  Engineer  Mr.  F.  Collingwood,  on  the  work  done  during  the 
previous  year,  indicates  some  of  the  troubles  and  dangers  encountered  in 
prosecuting  the  work.  The  completion  of  the  tower  from  about  the 
roadway  to  the  top  was  entrusted  to  him,  and  as  the  pioneer  in  having  to 
meet  all  the  untried  difficulties  in  construction  at  this  height,  he  is  de- 
serving of  great  credit  for  the  entire  freedom  from  accident  and  the  suc- 
cess of  the  work.  The  stone  stored  here  are  already  charged  to  the 
several  structures  for  which  they  are  designed ;  aside  from  these,  the 
machinery,  engines,  derricks,  tools,  supplies,  materials  and  office  furniture 
on  hand,  together  with  the  stone  scows,  inventory  at  $21,037. 

A  large  amount  of  work  has  been  done  in  the  Engineer's  office  in  the 
preparation  of  drawings  and  the  necessary  computations  for  the  foot- 
bridge and  cradle-ropes,  and  of  designs  for  the  New  York  approach. 
This  work  has  been  efficiently  done  by  Mr.  Wm.  Hildenbrand. 

A  large  number  of  maps  of  property  have  been  made  by  Mr.  B.  G-. 
Lingeman,  who  excels  in  this  class  of  work. 

Mr.  McNulty  has  spont  all  his  available  time  in  the  office  in  making 
the  drawings  of  attachments  for  the  temporary,  and  also  for  the  perma- 
nent cables,  of  the  machinery  for  strand  and  cable-making,  in  miscella- 
neous computations  and  other  work,  and  especially  in  designing  machinery 
for  propelling  the  passenger  cars  on  the  bridge. 

Since  the  stone  yard  at  Red  Hook  was  closed  up,  Mr.  Vanderbosch  has 
rendered  valuable  assistance  on  the  designs  for  the  New  York  approach. 

To  Mr.  0.  P.  Quintard,  the  gentlemanly  and  efficient  Book-keeper  and 
Secretary  of  the  Board  of  Trustees,  the  Pmgineer's  Department  is  under 
great  obligations  for  the  cheerfulness  with  which  all  information  required 
from  his  department  has  been  furnished. 

Mr.  J.  C.  Moore  has  held  the  position  of  Receiving  Clerk  and  Time- 
keeper during  the  last  two  years,  and  lias  performed  his  duties  in  a  highly 
creditable  and  satisfactory  manner. 

The  report  of  Col.  Paine  covers  the  operations  at  the  New  York 
Tower  for  the  past  two  years.  During  that  time  7,356  cubic  yards  of 
masonry  have  been  laid,  and  everything  got  in  readiness  for  cable- 
making.  The  large  amount  of  stone-cutting  to  be  done  this  year  to  pre- 
pare beds  for  the  saddle-plates  and  grooves  for  the  long  bars,  also  in 


90 


dressing  up  the  V  course  at  the  springing  of  the  arches,  has  considerably 
increased  the  labor  on  this  portion  of  the  masonry.  The  estimate  for 
completion,  however,  shows  a  slight  saving  over  that  made  last  year, 
and  everything  indicates  a  faithful  and  economical  prosecution  of  the 
work. 

In  addition  to  his  other  duties,  Col.  Paine  has,  by  your  direction,  con- 
tinued the  admirable  series  of  tests  on  steel  wire.  These  are  probably 
more  complete  and  accurate  than  any  that  have  ever  preceded  them,  ad- 
vantage having  been  taken  of  the  very  favorable  facilities  offered  by  the 
tower  for  testing  in  lengths  of  100  feet.  This  has  given  a  knowledge  of 
the  material  which  no  short  tests  could  possibly  yield,  particularly  of  the 
deleterious  effects  of  coiling  the  wire  in  small  coils  when  in  a  heated 
state  at  the  time  of  its  manufacture. 

The  operations  at  the  Xew  York  Anchorage  are  fully  detailed  in  the 
report  of  Mr.  Collingwood.  He  has  had  charge  of  this  work  from  the 
beginning,  and  his  plans  for  carrying  it  out  have  been  closely  followed 
and  have  thoroughly  approved  themselves  in  their  execution.  It  has 
been  really  one  of  the  most  remarkable  pieces  of  work  on  record;  during 
1875  nearly  16,000  yards  of  masonry  were  laid  in  four  months, 
and  during  1876,  11,000  yards  in  three  and  a  half  months,  notwithstand- 
ing the  interruptions  caused  by  raising  derricks,  putting  anchor-chains 
and  plates  in  position,  and  inserting  the  numerous  bars  and  attachments 
needed  in  cable-making,  and  for  temporary  works  connected  therewith. 

This  is  almost  the  only  case  in  which  we  have  had  sufficient  material 
on  hand  to  allow  the  work  to  proceed  with  all  possible  dispatch. 

As  soon  as  stone-setting  was  completed,  the  stone  remaining  at  Red 
Hook  was  brought  up  and  stored  as  follows : 

Cubic  yards. 


Limestone  at  Brooklyn  Tower  yard   388.0 

Granite  for  Brooklyn  Tower,  at  Brooklyn  Tower  yard   208.0 

"     for  Brooklyn  Anchorage,  at  Brooklyn  Tower  yard   56.3 

for  N".  Y.  Tower,  at  Pier  29   230.3 

"  "       Anchorage,  at  N.  Y.  Anchorage   68.5 

Limestone  for  N.  Y.  Anchorage,  at  N.  Y.  Anchorage   108.8 


Total  stone  charged  to  the  several  structures   1,059.9  yds. 


594  yards  of  Limestone  are  also  stored  at  the  Brooklyn  Tower  for 
Messrs.  Noone  &  Madden,  being  amount  sent  in  excess  of  contracts  ;  also 
63  Granite  corners  for  Messrs.  Pierce  &  Rowe.  Arrangements  were 
made  with  these  parties,  by  which  we  were  to  store  the  stone,  and  if  at 
any  future  time  we  shall  use  them,  they  are  to  be  paid  for  at  the  then 
current  price. 

After  storing  the  stone,  the  yard  at  Red  Hook  was  dismantled,  all 
engines,  derricks,  etc.,  removed  and  stored  for  future  use,  and  the  lease 
of  the  yard  was  surrendered,  thus  cutting  off  that  item  of  expense. 


91 


Now  that  the  yard  has  been  cleared  up  aud  the  stone  left  on  hand  ac- 
curately measured,  a  satisfactory  reply  can  be  made  to  all  questions  con- 
cerning the  amount  used  in  the  masonry,  and  one  which  is  capable  of 
exact  verification. 

There  have  been  received  on  all  contracts  for 

Average 

Cubic  Yards.     Price  per  yd.         Total  Price. 

Granite  69,0791|  $21.83  $1,507,706  02 

Limestone  46,556|i  13.40  623,561  32 

Or  a  total  of   115,636$A  $2,131,267  84 

The  stone  on  hand  not  laid 

as  given  above  measure  l,059Ji- 

Leaving    stone  actually 

placed  in  masonry   114,576^.1 

A  careful  computation  of  the  total  bulk  of  the  masonry  now  in  place 
(including,  of  course,  the  concrete  and  mortar  joints),  made  by  taking 
the  exact  dimensions  of  each  piece  of  masonry,  gives  the  following 
quantities,  viz. : 

Total  when 

Am't  now  Laid.        Am't  to  be  Laid.  Completed. 
New  York  Anchorage. .  25,897$  2,986      '  28,883$ 

Brooklyn  Anchorage....  24,132  2,981  27,113 

New  York  Tower   46,700$  243$  46,944 

Brooklyn  Tower   37,995  220  38,215 

Totals   134,724|.yds.  6,430$  yds.       141,155$  yds. 

Cubic  Yards. 

Total  amount  of  masonry  as  thus  found  to  be  now  laid   134,7246. 

Total  stone  used  in  masonry  as  shown  by  previous  paragraph  114,576^-1 


Excess  of  masonry  over  stone  used  20, 147|- 

It  is  thus  shown  that  the  mortar  and  concrete  spaces  make  up  about  15 
per  cent,  of  the  total  mass.  This  also  explains  another  fact,  viz. :  that  in 
the  first  contracts  made,  where  the  spaces  were  estimated  at  only  10  per 
cent.,  there  was  always  an  excess  of  stone  beyond  the  amount  required. 

It  may  be  of  interest  to  insert  here  a  summary  of  all  the  materials  used 
in  concrete  and  mortar  for  the  whole  work. 

Cubic  Yards. 

The  total  contents  of  masonry  joints  as  found  above  are   20,147 

The  concrete  filling  in  and  around  the  caissons,  and  in  the  well- 
holes  aggregate  about   14,883 


Making  a  total  of. 


35.030 


92 


The  exact  amount  of  material  required  for  this  it  is  impossible  to  ac- 
curately estimate,  but  making  due  allowance  for  shrinkage,  it  would  be 
approximately  57,000  yards  of  sand,  gravel  and  broken  stone.  Of  this 
there  were  bought, 

75,119  barrels  of  cement,  costing   $116,740  98 

24,328  yards  of  gravel,       "    41,218  18 

4,098  yards  of  stone,        "    4,764  69 

8,735  yards  of  sand,         "    7,594  17 

Total,  37,161  yards  of  material  aside  from  cement  $170,318  03 

This  shows  that  about  20,000  yards  of  sand,  gravel,  stone  and  brick 
were  saved  from  the  several  excavations.  The  value  of  the  material  thus 
saved  and  utilized  is  at  least  $25,000. 

The  progress  thus  far  made  in  putting  up  the  temporary  work  for  use 
in  making  the  cables,  is  fully  detailed  in  the  report  of  the  Master  Me- 
chanic, Mr.  E.  F.  Farrington. 

The  severe  storms  of  the  season  make  the  progress  slow  at  present, 
but  without  doubt,  the  foot-bridge,  cradles  and  appendages,  will  be  in 
position  in  time  to  enable  work  upon  the  cables  to  be  started  in  the  early 
spring. 

The  amount  expended  this  year  on  this  branch  of  the  work  for  labor 
and  all  contingent  expenses,  has  been  $94,056.42. 

In  addition  to  preparations  for  cable-making,  Mr.  Farrington  has  had 
charge  of  the  carpenter  work  and  of  the  blacksmith  shop. 

The  amount  expended  during  the  past  year  for  real  estate,  has  been 
$439,031.24.  This  includes  all  legal  expenses  paid  during  the  year,  in 
connection  with  these  and  other  land  purchases,  and  all  repairs  of  build- 
ings. With  the  exception  of  a  few  pieces  yet  to  be  taken,  this  covers  the 
entire  cost  of  property  between  the  tower  and  anchorage  on  both  sides  of 
the  river,  which  remained  to  be  taken  at  the  beginning  of  the  year.  The 
considerable  saving  thus  fur  made  seems  to  indicate  that  the  estimate  of 
1873  for  the  cost  of  all  the  land  would  in  no  case  be  exceeded. 

I  cannot  close  this  report  without  a  word  in  reference  to  the  work  at 
the  Red  Hook  stone  yard.  Since  we  have  occupied  that  yard,  about 
116,000  cubic  yards  of  stone  have  been  received,  and  they  have  varied  in 
weight  from  one  to  eleven  tons  each.  They  have  been  unloaded  from  the 
vessels,  which  brought  them  from  the  quarries,  and  stored  in  the  yard ; 
and  as  ihey  were  required  for  the  work  they  were  taken  from  the  piles 
in  which  they  had  been  placed,  and  loaded  upon  scows.  This  made  four 
times  at  least  that  each  stone  was  lifted,  and  many  of  them  several  times 
in  addition,  owing  to  the  fact  that  the  stone  were  never  delivered  exactly 
in  the  order  required  by  the  contract  All  of  this  work,  which  would  at 
a  low  estimate  amount  to  handling  500,000  cubic  yards  of  stone  once,  has 
been  done  without  any  accident  worth  mentioning,  either  to  men  or  ma- 
chinery.   The  yard  has  been  in  charge  of  Mr.  Frank  Mollard,  to  whose 


93 


constant  watchfulness  and  knowledge  of  this  kind  of  work,  this  immunity 
from  accident  is  largely,  if  not  entirely,  due.  All  of  the  stone  received 
have  been  measured  and  inspected  by  Mr.  Win .  Vanderbosch ;  and. 
although  his  inspection,  in  some  cases,  seemed  to  the  contractors  to  be 
too  severe,  yet  his  knowledge  of  the  quality  of  stone  and  the  require- 
ments of  the  specifications,  coupled  with  his  evident  desire  to  deal  justly, 
has  in  the  end  satisfied  all  parties.  His  difficult  and  delicate  task  has 
been  conscientiously  and  faithfully  performed. 

With  regard  to  the  future  work  of  cable-making,  I  think  I  may  safely 
say  that  no  difficulty  need  be  apprehended  in  securing  the  services  of  men 
to  go  anywhere  or  do  anything.  In  the  suspended  work  thus  far  accom- 
plished, there  has  been  a  spirit  of  rivalry  among  our  best  men  as  to  who 
should  be  assigned  to  the  most  dangerous  and  difficult  tasks ;  and  Mr. 
Farrington  has  had  constantly  to  hold  them  back  to  prevent  their  taking 
dangerous  but  unnecessary  risks.  During  the  year  Mr.  Thomas  G-. 
Douglas,  General  Superintendent  of  Masonry,  died  He  had  held  that 
position  from  the  commencement  of  work  on  the  masonry — having  set 
the  first  stone  on  the  Brooklyn  Tower — and  he  lived  to  see  nearly  the 
last  stone  set  on  the  Xew  York  Tower,  and  the  towers  and  anchorages 
grow  into  their  present  grand  proportions. 

"Win.  Conners,  a  foreman  of  masons,  who  built  a  considerable  portion  of 
both  towers,  also  died  during  the  year. 

The  organization  of  the  working  force  for  the  season  has  not  been 
essentially  changed. 

Mr.  C.  TV.  Young  still  holds  the  position  of  General  Foreman  of  labor, 
and  Mr.  A.  H.  Smith  is  Foreman  of  the  machine  shop.  "We  seem  to 
have  the  right  men  in  the  right  places,  for  the  work  has  moved  forward 
rapidly  and  with  very  little  friction. 

Respectfully  submitted. 

C.  C.  MARTIX. 

Assistant  Engineer. 

Brooklyn,  December  31,  1876. 


BROOKLYN  TOWER.  1575. 

Col.  W.  A.  Roebling, 

Chief  Engineer  of  the  New  York  and  Brooklyn  Bridge. 

Dear  Sir: 

I  would  respectfully  submit  the  following  report  upon  the  work 
done  on  the  Brooklyn  Tower  during  the  season  of  1875 : 

The  work  on  masonry  closed  December  12,  1874.  Immediately  after- 
ward the  saddle-plates  were  taken  to  the  top  of  the  tower,  and  a  force  of 
stone-cutters  set  at  work  preparing  the  beds  for  them.  This  work  was 
finished  early  in  January. 


94 


During  the  winter  the  arch  centres  were  all  removed,  and  the  material 
which  was  useless  for  general  purposes)  was  afterwards  taken  to  the 
New  York  Anchorage,  for  use  in  the  foundation  of  that  structure 

Regular  work  on  the  tower  began  about  the  middle  of  April,  when  the 
saddle-plates  were  set,  and  the  saddles  hoisted  and  moved  to  their 
places.  Every  stone  was  then  set  that  could  be  before  cable-making,  the 
roof  joints  caulked,  and  the  work  brought  to  a  close  about  the  middle  of 
June.  In  order  to  avoid  the  errors  of  dimension  which  were  sure  to 
creep  in  from  irregularities  in  stone-cutting,  and  running  up  masonry  to 
this  great  height  by  the  use  of  the  plummet  and  line  only,  frequent 
measurements  of  the  exterior  lines  were  made,  and  all  referred  to  central 
transit  lines,  which  were  themselves  referred  to  points  fixed  upon  distant 
buildings.  Levels  were  also  made  over  the  whole  surface,  and  trans- 
ferred by  vertical  measurements  to  a  bench  mark  in  the  yard  below.  By 
this  means  the  joints  were  kept  to  their  proper  thickness,  and  we  were 
enabled,  by  a  minimum  amount  of  stone  dressing,  to  set  the  saddle-plates 
at  exactly  the  height  required.  In  setting  the  archstones  every  piece 
of  lagging  for  them  was  put  in  position  by  level  and  measurements  from 
transit  lines. 

The  finishing  up  of  the  masonry  was  a  work  of  considerable  difficulty 
and  danger,  as  many  of  the  roof  stones  weighed  from  nine  to  ten  tons 
each  (the  key-stones  weighed  eleven  tons  each) ;  and  it  was  difficult  to 
properly  support  the  derricks,  which  were  not  balanced  to  support  so 
great  a  weight. 

The  risk  was  considered  so  great,  that  one  of  the  engineer  corps  was  in 
constant  attendance  whenever  stone-setting  was  being  done. 

One  other  cause  of  danger  arose  from  the  great  length  and  weight  of 
the  hoisting  ropes  of  the  main  hoist.  •  These  were  steel  wire  ropes  l£ 
inch  diameter,  and  had  reached  lengths  from  the  drums  to  the  sheaves  at 
top  of  the  tower  of  350  feet  each.  The  vibrations  in  them  caused  by  the 
pulsations  of  the  engine  frequently  became  so  violent  as  to  require  a 
stoppage  or  change  of  motion  of  the  latter. 

The  final  effect  was  a  succession  of  surges  on  the  stone,  requiring  extra 
care  in  the  attachments  for  hoisting.  For  this  purpose  extra  large 
lewises  were  used,  and  a  very  careful  man  was  placed  on  the  scow  at  the 
base  of  the  tower  to  examine  all  the  holes  and  drive  the  lewises.  In 
spite  of  this  care,  however,  the  granite  failed  in  a  few  instances,  spalling 
out  for  two  feet  around  the  hole.  In  only  one  case  did  a  stone  fall. 
This  was  after  reaching  a  height  of  200  feet.  It  did  no  damage  beyond 
completely  demolishing  the  tracks  underneath  and  burying  itself  in  the 
ground. 

One  of  the  greatest  difficulties  experienced  was  that  of  making  effective 
signals  to  the  engineer  in  the  yard  below,  so  as  to  prevent  overwinding. 
Sound  was  often  of  no  avail  owing  to  the  high  wind  ;  sight  was  sometimes 
partially  obscured  by  fog,  and  signal  bells  were  'constantly  out  of  order 
from  the  wires  getting  broken. 


95 


The  attachments  on  the  tower  were  all  made  abundantly  strong,  and, 
although  a  few  cases  of  overwinding  occurred,  no  accident  resulted  in 
consequence. 

The  most  effective  signals  were  found  to  be  a  loud  whistle  to  call 
attention,  and  a  flag  used  with  a  very  positive  motion  to  indicate  what 
was  required. 

It  is  a  great  satisfaction  to  be  able  to  state  that,  during  the  building  of 
all  that  portion  of  the  work  which  is  above  the  roadway  (by  far  the  most 
difficult  part),  there  has  been  no  accident  to  life  or  limb.* 

A  narrow  escape  occurred  whilst  transferring  the  last  of  the  saddles 
from  the  elevated  track  at  top  of  the  tower  to  the  masonry.  This  was 
done  by  the  traveling  crane;  and  while  the  weight  of  13^  ton3  was 
suspended  just  over  the  edge  of  the  masonry,  the  hook  of  the  upper 
block  began  to  straighten.  It  stopped  fortunately  after  opening  an  inch, 
and  the  saddle  was  quickly  lowered  and  secured. 

The  application  of  steam  to  the  setting  derricks  has  saved  a  consider- 
able amount  of  time,  and  no  difficulty  was  found  in  carrying  the  steam  to 
the  top  of  the  work,  requiring  a  length  of  about  four  hundred  feet  of 
pipe. 

The  trestling  and  stairway  have  been  carried  to  the  extreme  height 
that  will  be  required.  The  hoisting  frames  have  been  removed,  and  the 
top  cleared  of  all  obstructions. 

The  amount  of  masonry  set  during  the  year  is  497  yards,  leaving  220 
yards  to  be  set  after  cable-making  to  complete  the  tower,  aside  from 
parapets. 

The  total  expenditure  on  masonry,  including  stone  on  hand 

for  completion,  has  been   $32,348  55- 

A  further  sum  has  been  expended  at  this  yard  for  repairs  of 

dock,  watchman,  stableman,  messenger,  etc.,  of   2,839  34 

The  four  saddles  weighing  a  total  of  103,423  lbs.,  the  four 
plates  weighing  81,595  lbs.,  and  180  rollers  weighing 
25,260  lbs.,  including  the  labor  of  preparing,  hoisting  and 

placing  them,  have  cost  a  total  of   10,701  17 

This  is  a  saving  of  nearly  $1,800  on  the  estimate  of  1873. 

The  machinery  and  material  at  the  Brooklyn  Tower  and  yard, 

together  with  the  furniture  in  the  offices,  inventory  at  . . .     32,486  70 

I  ought  not  to  close  this  report  without  a  brief  statement  respecting  its 
stability  as  thus  far  shown.     "When  the  masonry  was  but  a  few  feet 

*  This  result  has  only  been  secured  by  incessant  watchfulness  on  the  part  of 
engineer  and  foreman.  On  one  occasion  four  men  were  pulling  on  a  tackle  with 
their  backs  to  the  edge  of  the  wall.  They  were  told  to  change  about,  so  that  in 
case  anything  broke  they  would  be  safe  from  harm.  Almost  immediately  after 
straining  up  again,  the  hook  of  one  of  the  blocks  straightened.  Had  this  hap- 
pened at  first  they  would  have  inevitably  been  precipitated  over  the  edge  of  the 
masonry.  Sudden  gusts  of  wind  of  great  violence  required  a  constant  watchful, 
ness  to  prevent  being  blown  off  the  wall  by  losing  balance  when  near  the  edge. 


96 


above  high  water,  reference  marks  were  fixed  in  the  masonry  at  four  feet 
above  tide  at  each  of  the  salient  angles  and  levels,  carefully  made  upon 
them,  and  referred  to  a  stationary  bench  mark  on  a  building  some  dis- 
tance away.  Recent  levels  have  been  made  upon  the  same  points 
and  they  show  an  average  settlement  caused  by  the  mass  of  masonry 
added,  of  only  1^  inches,  with  an  extreme  variation  between  any  two 
points  of  only  \  of  an  inch. 

Respectfully  submitted, 

F.  COLLINGWOOD, 
Assistant  Engineer  in  charge. 

Brooklyn,  December  31,  1875. 


N.  Y.  TOWER.  1875-1876. 

Col.  W.  A.  Roebling, 

Chief  Engineer  of  the  New  York  and  Brooklyn  Bridge. 

Dear  Sir  : 

I  have  the  honor  to  present  the  following  report  of  such  operations 
connected  with  the  construction  of  the  East  River  Bridge  as  have  been 
entrusted  to  my  charge  during  the  past  year,  and  also  a  condensed  state- 
ment of  the  report  made  to  you  respecting  the  work  done  in  1875 : 

The  work  of  laying  masonry  on  the  tower  was  resumed  April  30, 
1875,  at  the  point  where  it  closed  in  the  previous  December,  being  at  the 
top  of  the  120th  course  at  the  springing  of  the  arches,  196y6i_.  feet 
above  mean  high  tide. 

There  were  two  long  and  vexatious  delays,  amounting  in  all  to  82  work- 
ing days  during  that  season.  These  were  caused  by  the  stone  contractors 
not  being  prompt  in  the  delivery  of  stone.  The  work  of  stone- setting  for 
that  season  was  finally  suspended  on  the  27th  of  November  for  the  same 
cause,  at  the  top  of  the  139th  course,  being  the  top  of  the  key-stones  of 
the  arches,  and  had  a  height  above  tide  of  239JL*_  feet. 

The  height  laid  during  1875  was  43-2JL.  feet,  leaving  31^UB_  feet  to 
complete  the  tower,  requiring  about  ten  weeks  of  uninterrupted  work — a 
less  space  of  time  than  had  been  lost  by  delays. 

The  quanity  of  masonry  laid  during  the  season  was  3,806  cubic  yards, 
using  3,385  cubic  yards  of  stone. 

The  total  cost  of  masonry  for  the  season,  including  labor, 

material  and  all  expenses,  was   $105,994  70 

The  end  of  the  dock  was  repaired  at  an  expense  of   461  03 

The  saddles  and  saddle-plates  were  on  the  dock  and  ready 
to  be  placed  in  position.    Their  total  weight  is  183,107 

lbs.,  and  their  cost  was   5,949  27 

There  were  65  yards  of  granite  for  use  on  tower  stored  here  and  at 

Red  Hook,  which  had  been  paid  for,  aside  from  a  large  quantity  at  Red 


97 


Hook  received,  but  not  then  estimated  for  on  account  of  the  courses  not- 
being  completed. 

The  value  of  other  materials,  supplies,  machinery,  tools, 

and  furniture  in  this  yard,  inventoried  at   $36,760  85 

The  estimated  cost  of  completing  the  tower  was   136,800  00 

All  of  the  masonry  above  high  tide  had  been  carefully  examined  during 
the  year,  and  rfjointed  where  it  was  necessary.  A  considerable  force  of 
carpenters  had  been  emploj'ed  in  erecting  the  arch  centres,  removing  the 
traveling  crane  and  erecting  a  balance  derrick  on  the  centre  shaft;  also 
in  building  up  the  scaffolding  as  the  work  progressed. 

Passing  from  the  work  of  1875,  the  masonry  of  the  New  York  Tower, 
which  at  the  close  of  that  year  had  reached  a  height  of  -239-SJL.  feet,  has 
during  this  year  been  finished,  excepting  the  parapets  and  such  porticns 
of  the  three  upper  courses  as  could  not  be  laid  without  interference  with 
the  cable-making. 

The  present  height  of  the  tower  to  the  top  of  the  roof  course  is  271-^3, 
feet,  making  a  height  of  31.^6^.  feet  laid  this  year.  The  amount  of 
masonry  laid  has  been  3,550  cubic  yards. 

The  work  of  laying  the  masonry  was  resumed  on  the  11th  of  April,  a 
small  amount  of  stone-cutting  having  been  previously  done.  Only  one 
gang  of  masons  was  employed  during  the  season,  and  they  were  often 
delayed  by  the  stone-cutting  required  to  be  done. 

The  stone-setting  was  completed  on  the  24th  of  July,  after  which  time 
several  masons  and  stone-cutters  were  employed  until  November  13  in 
trimming  and  pointing  all  the  masonry  of  the  tower  that  remained 
unfinished. 

I  ought  here  to  express  my  gratification  at  the  manner  in  which  the 
work  on  the  tower  has  been  done. 

Mr.  D.  J.  Cowan  proved  himself  to  be  a  competent,  careful  and  reliable 
foreman  of  masons. 

Mr.  Harry  Supple  was  all  that  could  be  desired  as  foreman  of  riggers 
and  laborers  on  the  tower,  while  Mr.  O.  B.  Poor  showed  his  capability  of 
taking  charge  of  the  men  variously  employed  upon  the  dock. 

The  total  amount  expended  during  the  past  year  on  masonry, 
including  a  due  proportion  of  all  office  and  contingent  ex- 


penses, and  the  stone  stored  for  future  use,  has  been  $121,979  90 

The  amount  previously  expended  was   1.040,065  00 


The  total  amount  expended  to  date,  is  $1,162,044  90 

The  estimate  as  revised  last  winter,  was   1,176,865  00 

Leaving  amount  of  estimate  unused    $14,820  10 

The  estimated  cost  of  completion  from  this  date,  is    14,778  00 


Showing  a  small  saying  on  estimate  of  Jan.  I,  1876,  of  ... .  $42  10 

7  " 


98 


The  amount  of  masonry  yet  to  be  laid,  is  243£  yards,  for  which  the 
stone  are  now  stored  at  this  yard. 

The  machinery,  tools,  supplies,  furniture,  derricks,  etc.,  on  hand  at  this 
yard  (not  including  stone  stored  for  future  use),  inventories  at 
$25,113. 

It  is  here  proper  to  call  attention  to  the  fact  that  the  stone  and  all  other 
materials  required  during  the  past  two  years  for  the  construction  of  the 
New  York  Anchorage,  have  been  received  at  this  pier,  giviug  an  oppor- 
tunity of  employing  all  the  labor  economically. 

The  blacksmith  and  machine  work  for  the  Anchorage  and  for  cable- 
making  have  also  been  done  here. 

During  the  past  four  years  I  have  endeavored  to  carry  out,  as  fully  as 
circumstances  would  permit,  your  instructions  in  regard  to  experiments 
with  and  tests  of  wire,  and  have  conducted  them  with  the  objects  which 
you  desired,  kept  in  view. 

The  experiments  relative  to  the  properties  requisite  in  the  cable-wire 
to  meet  all  that  will  be  required  of  it,  have  been  made  with  great  care; 
while  the  tests  of  wire  for  the  purposes  of  ascertaining  the  possibility  of 
meeting  these  requirements,  have  been  very  large  in  number,  and  com- 
prehensive in  their  range,  and  have  occupied  much  time. 

Besides  the  wire  that  has  been  directly  ordered  of  different  parties  in 
this  and  other  countries,  many  other  samples  have  been  received  from  a 
large  number  of  different  manufacturers.  Added  to  this,  the  testing  of 
all  the  wire,  used  in  making  the  foot-bridge  ropes,  which  now  span  the 
river,  has  given  unusual  opportunities  of  becoming  acquainted  with  all 
the  properties  of  steel  wire,  that  can  be  practically  obtained  and  relied 
upon.  The  experiments  and  tests  have  been  conducted  with  a  view  of 
harmonizing  that  which  is  desirable,  on  the  one  part,  with  that  which  is 
attainable  on  the  other,  in  a  practical  and  economical  manner.  Full  and 
complete  records  have  been  kept  of  the  results  of  all  the  experiments  and 
tests  that  have  been  made.  As  the  results  have  been  placed  before 
you,  from  time  to  time,  and  I  have  all  along  been  guided  by  your  in- 
structions, I  need  not  further  dwell  on  this  subject,  than  to  express  my 
satisfaction,  in  regard  to  the  fact,  that  although  the  specifications  call  for 
wire,  in  some  respects  superior  to  any  ever  before  produced,  they  have 
been  met  so  fully  by  the  sample  s  presented  by  bidders.  In  all  this  work 
I  have  been  ably  assisted  by  Mr.  C.  H.  Piatt,  who,  from  his  knowledge 
of  engineering,  has  rendered  aid  of  every  character,  for  which  I  had 
occasion  to  call  upon  him. 

Very  respectfully  submitted, 

W.  H.  PAINE, 

Assistant  Engineer. 

New  York,  December  31,  1876. 


99 

NEW  YORK  ANCHORAGE.  1875-1876. 

Col.  W.  A.  Roebling, 

Chief  Engineer  of  the  New  York  and  Brooklyn  Bridge. 

Dear  Sir: 

I  would  respectfully  present  the  following  report  as  to  the  work  thus 
far  done  upon  the  New  York  Anchorage,  beginuiug  with  the  report  writ- 
ten a  year  ago  upon  the  work  of  1875. 

The  property  upon  which  the  Anchorage  stands  was  paid  for  early  in 
April. 

Full  possession  was  not  obtained  until  the  6th  of  May,  when  the  de- 
molition of  the  buildings,  and  the  excavation  for  the  foundation  were  *at 
once  entered  upon. 

Owing  to  the  late  letting  of  the  contract  for  material  for  the  railroad 
through  Roosevelt  and  Water  streets,  the  work  of  laying  down  the  tracks 
could  not  be  started  until  May  28th.  It  was  completed  by  June  21st  so 
that  dirt  cars  could  be  run  over  it  to  Pier  29,  and  a  week  later  all  hauling 
with  carts  was  stopped. 

The  temporary  hoisting  derricks  were  ready  for  use  June  19th,  and  the 
work  of  sheeting  and  bracing  the  banks  of  the  pit  began  at  the  same  date. 
The  work  of  bringing  the  material  for  this,  and  for  the  permanent  struct- 
ure to  the  Anchorage,  was  very  much  facilitated  by  the  railroad. 

The  tracks  run  almost  entirely  through  narrow  streets,  but  by  a  judi- 
cious use  of  curves  and  switches,  all  serious  stoppages  even  during  busi- 
ness hours  have  been  avoided.  The  cost  of  the  railroad  was  about 
$6,000,  being  considerably  less  than  the  estimate. 

By  June  21st  the  excavation  had  so  far  progressed  as  to  make  it  nec- 
cessary  to  begin  pumping  to  free  the  pit  from  water. 

At  first,  two  No.  4  Niagara  pumps  were  used,  but  by  July  3d  it  be- 
came necessary  to  add  an  Andrews'  centrifugal  pump. 

From  this  date  for  four  weeks,  the  quantity  of  water  thrown  out  aver- 
aged about  600  gallons  per  minute.    Pumping  finally  ceased  August  21st. 

The  actual  work  of  excavation  was  very  expensive,  owing  to  the  mas- 
siveness  and  solidity  of  the  numerous  foundations  to  be  removed.  In  some 
of  these  the  cement  was  so  solid  as  to  make  it  necessary  to  break  them 
up  with  fledges. 

I  estimate  the  quantity  of  stone  and  broken  brick  saved  (aside  from 
the  brick  sold)  to  have  been  about  1,100  yards.  This  has  more  than  sup- 
plied all  the  materials  of  the  kind  needed  thus  far,  for  the  vertical  spaces 
in  the  masonry. 

The  sand  and  gravel  saved  was  but  1,000  yards  ;  the  remainder  ol  the 
excavated  material  being  totally  unfit  for  use. 
This  was  quite  contrary  to  previous  expectations. 

A  considerable  saving  was  made  in  the  amount  of  sheeting  required,  by 


100 


allowing  the  basement  walls  along  Dover  street  to  stand  until  after  the 
foundation  was  completed. 

An  additional  saving  was  made  by  giving  wider  spaces  between  the 
braces  than  was  adopted  at  the  Brooklyn  Anchorage. 

This,  with  other  modifications,  gave  much  freer  working  room,  and 
greatly  facilitated  subsequent  operations. 

The  present  bulkhead  line  on  the  East  river  is  about  600  feet,  in  ad- 
vance of  the  old  shore;  the  intervening  space  having  been  filled  in  and 
covered  by  blocks  of  substantial  buildings.  Our  excavation  showed  that 
the  old  saore  line  passed  directly  across  the  Anchorage  site,  but  was  not 
so  regular  in  outline  as  previous  examination  had  lead  us  to  infer. 

At  the  corner  nearest  Dover  and  Water  streets,  the  clear  sand  below 
the  mud  was  found  at  about  7  feet  below  mean  high  tide.  At  this  point 
a  large  quantity  of  spent  tan  bark  had  in  time  past  been  dumped  into  the 
water,  on  top  of  which  was  the  ordinary  dirt  filling.  This  was  no  doubt 
the  refuse  from  the  tanneries,  so  long  ago  established  in  the  "  Swamp." 
For  the  rest  of  the  distance  across  the  front  the  average  depth  was  about 
5  feet  below  tide. 

At  about  the  centre  line  of  the  excavation,  and  also  on  the  east  side, 
there  were  indentations  running  back  to  near  the  centre  of  the  pit.  One 
of  these  was  entirely  filled  with  peat,  which  must  have  grown  when  the 
island  was  in  its  native  state. 

At  about  the  depth  of  high  water,  an  old  dock,  long  since  buried, 
was  uncovered.  This  ran  entirelv  across  the  pit,  and  the  front  edge  was 
nearly  parallel  with  Water  street,  at  about  thirty  feet  from  it.  It  was 
about  twenty  feet  wide,  and  four  feet  deep.  The  logs  composing  it  were 
from  six  inches  to  thirty  inches  in  diameter,  and  were  all  p'-rftctly  sound 
after  their  long  burial.*  As  they  extended  under  the  sheeting  at  both 
sides,  and  had  to  be  cut  off  under  water,  they  caused  a  great  deal  of 
trouble  in  driving  the  planks. 

A  large  number  of  pieces  of  fossil  coral  were  found  in  front  of  the 
dock;  this  is  supposed  to  have  been  ballast,  which  was  thrown  over- 
board from  vessels  previous  to  the  river  being  encroached  upon.  In  the 
course  of  the  excavation  two  four-pound  cannon  balls,  whose  history 
would  no  doubt  be  of  interest  could  it  be  told,  were  found  buried  deep  in 
the  sand. 

Before  beginning  the  foundation,  every  particle  of  mud  and  other  com- 
pressible material  was  removed.  As  the  mud  ran  deeper  than  had  been 
anticipated,  it  was  deemed  advisable  to  extend  the  timber  grillage  at  the 
front,  about  eight  feet  in  advance  of  the  original  plan.  In  addition  to 
this,  the  grillage  was  by  your  order  placed  four  feet  lower  than  that  of 
the  Brooklyn  Anchorage,  or  so  that  the  top  of  it  was  level  with  high  tide. 
By  these  and  other  changes,  the  quantity  of  excavation  was  increased 

*  As  a  proof  of  this,  some  of  them  were  used  afterward  in  bracing  the  founda- 
tion under  end  pressures  of  seventy  tons,  on  sticks  14  x  14  x  25  feet. 


101 


about  2,500  yards,  and  the  quantity  of  masonry  about  2,000  yards,  over 
previous  estimates. 

The  sheeting  across  the  entire  front  and  east  side,  and  partly  across 
the  other  side  and  end,  was  driven  to  two  feet  below  the  foundation,  and 
allowed  to  remain,  as  a  further  precaution  against  possible  settlement. 

Care  was  taken  with  all  the  back  filling,  to  allow  none  but  selected 
material  to  be  dumped;  and  all  was  thoroughly  compacted  by  a  water 
jet  as  it  was  thrown  in.  This  was  all  brought  from  other  works,  without 
cost  to  the  bridge. 

The  first  timber  of  the  foundation  was  placed  June  12th,  and  the  last 
dirt  sent  to  the  dump  June  14th. 

The  total  quantity  of  excavation  was  12,761  cubic  yards,  and  the  total 
cost  per  cubic  yard  was  $lyoV  This  includes  tearing  down  the  walls  of 
a  part  of  the  buildings,  and  all  of  the  foundations,  sheeting  and  bracing, 
pumping,  all  labor  at  the  pit  and  dump,  all  hoisting  and  transportation  of 
material,  the  hire  of  mud  scows,  and  the  cost  of  tools. 

In  constructing  the  grillage,  the  deep  space  in  front  was  entirely  filled 
by  partial  courses  of  timber  firmly  bolted,  and  with  concrete  filling  in  the 
spaces,  which  were  made  wide  for  that  purpose.  A  level  surface  over 
the  whole  foundation  was  reached  at  four  feet  below  tide,  and  from  this 
point  the  regular  courses  of  timber  were  started  according  to  the  original 
plan.  The  first  of  these  was  the  bearing  course,  with  three-inch  concrete 
spaces  where  it  rested  on  the  partial  courses,  and  nine-feet  spaces,  filled  with 
sand,  where  it  rested  on  the  sand.  The  second  course  had  one-inch 
cemented  spaces;  the  third  had  three-inch  concreted  spaces;  and  the 
fourth,  or  top  course,  had  six- inch  ditto.  The  bolting  was  systematic  and 
thorough,  about  10.000  bolts  20  inches  to  30  inches  long,  of  |  inch  iron, 
with  an  aggregate  weight  of  19  tons,  having  been  used. 

The  cubical  contents  of  the  foundations  are  about  1,840  yards,  and  the 
cost  per  yard  was  SllxoV  f°r  material  and  labor.  This  would  have 
been  about  $1  more,  had  new  timber  been  substituted  for  the  old  cen- 
tres and  other  waste  timber,  which  made  up  a  part  of  that  used. 

The  work  of  erecting  the  six  permanent  setting  derricks  was  begun 
August  14th,  and  completed  on  the  2Sth.  The  foundation  was,  however, 
completed  on  the  9th,  and  stone-setting  begun  on  the  5th  over  that  por- 
tion of  the  foundation  then  finished.  This  was  done  to  save  time,  and 
about  1,400  yards  were  thus  set  before  the  permanent  derricks  were 
ready. 

By  August  31st  everything  was  in  readiness  for  the  anchor-plates  to  be 
put  in  place;  but  owing  to  the  delays  in  awarding  the  contract  for  them, 
the  contractors  found  it  impossible  to  deliver  the  first  two  earlier  than 
September  7th,  and  the  remaining  two  did  not  arrive  until  the  25th.  This 
largely  increased  the  labor  of  setting  them,  by  making  it  necessary  to 
raise  thsm  above  the  masonry  which  had  meantime  been  laid,  and  to 
lower  them  into  the  holes  that  had  been  left  for  them,  which  were  about 
16  feet  deep. 


102 

In  bringing- the  plates  from  Pier  29,  the  railroad  was  brought  into  use 
with  a  considerable  saving  of  time  and  expense. 

For  this  purpose  a  heavy  framework  of  timber  was  made  strong  enough 
to  support  the  weight  (23  tons)  of  each  plate,  and  of  a  length  of  30  feet, 
or  sufficient  to  span  the  space  between  the  centres  of  two  cars,  when 
the  plate  hung  freely  between  them. 

The  frame  was  pivoted  at  each  end,  and  rested  on  heavy  oak  bolsters, 
so  as  to  allow  the  cars  to  take  the  railroad  curves  easily. 

As  a  precaution,  the  curves,  one  of  which  had  but  34  feet  radius,  were 
soaped  before  starting. 

The  plates  were  17£  feet  by  16  feet  in  size,  making  it  necessary  to  re- 
move a  lamp-post  and  some  other  obstructions. 

When  all  was  ready,  three  teams  of  horses  were  attached,  and  the 
heavy  weights  were  each  taken  over  the  1,000  feet  of  track  between  the 
pier  and  anchorage  in  from  l£  to  2  minutes. 

September  23d  the  masonry  had  been  brought  entirely  above  ground, 
all  the  sheeting  (except  that  heretofore  mentioned)  had  been  withdrawn, 
and  everything  was  in  regular  working. 

A  night  gang  of  laborers  was  organized  June  21st  to  facilitate  the  ex- 
cavation, and  continued  for  this  and  other  purposes  throughout  most  of 
the  season.  About  the  middle  of  September  a  night  gang  of  masons 
was  put  on.  The  experience  has  been  that  such  work  as  concreting,  and 
the  rougher  parts  of  mason  work  can  be  done  more  economically  at  night, 
owing  to  entire  freedom  from  delays  in  the  transportation  of  material. 

By  November  4th  the  masonry  had  progressed  so  as  to  require  the 
derricks  to  be  raised  28  feet. 

This  work  was  so  thoroughly  systematized  as  to  cause  a  delay  of  but 
8^  days. 

During  the  season  three  sets  of  anchor  bars  were  put  in  place. 
Thorough  inspections  have  been  made  from  time  to  time  of  the  iron  used, 
and  it  is  gratifying  to  state  that  the  quality  is  even  better  than  that  pre- 
scribed in  the  specifications  for  them.  Stone-setting  was  brought  to  a 
close  for  the  season  on  December  11th,  at  a  height  of  44^  feet  above  tide. 

Notwithstanding  the  fact  that  the  work  has  been  pushed  to  the  utmost, 
but  few  accidents  have  occurred,  and  none  of  these  were  of  a  fatal 
character. 

The  total  quantity  of  masonry  laid  this  season  is  14,892  cubic  yards,  at 
a  cost  (for  labor,  superintendence,  material,  supplies,  ^  cost  of  railroad, 
and  all  contingencies)  of  $14T3_2_  per  yard,  or  $3^^.  less  than  the  esti- 
mate of  1873,  the  total  cost  being  $213,290^-2-.. 

To  balance  this  saving  the  whole  anchorage  will  contain,  as  stated,  2,000 
yards  more  masonry  than  was  contemplated  in  1873,  of  which  1,600 
yards  belong  to  the  portion  now  in  place.  * 

This,  with  the  large  increase  mentioned  in  the  quantity  of  excavation, 
end  the  increased  cost  due  to  the  many  obstructions  met  with,  have  very 
nearly  balanced  the  saving  on  the  estimate. 


103 


The  railroad,  of  which  one-third  is  charged  to  work  of  this 

rear,  has  cost   $5,950  59 

The  total  cost  of  the  foundation,  including  the  excavation, 

has  been   36,589  24 


The  anchor-plates  weigh  an  aggregate  of  182,855  pounds, 
and  cost  in  place  (a  saving  of  about  40  per  cent,  on  the 
estimate  of  1S73)   $7,631  35 

559,900  pounds  of  anchor-bars  have  been  received  at  a 

cost  of  (about  25  per  cent,  less  than  the  estimate  of  1873)      33,034  10 

To  which  must  be  added  for  labor  in  putting  three  sets  in 

place   1,384  10 


Total  cost  of  anchor-bars  and  plates  thus  far   $42,049  55 

The  estimated  cost  of  completing  the  same,  is   36,992  00 


Total  estimated  cost  of  anchor-bars  and  plates  for  this  an- 
chorage   $79,041  55 

The  cost  of  the  structure  at  the  end  of  this  season's  work, 
including  the  total  cost  of  the  railroad  and  of  the  founda- 
tion, but  not  that  of  the  plates  and  chains,  was   253,847  22 

The  estimated  cost  of  completing  the  masonry  and  the  road- 
way  248,249  06 


Total  estimated  cost  of  the  structure  when  complete  $502,096  28 

The  machinery,  materials,  supplies  and  tools  on  hand  De- 
cember 31,  1875,  at  this  yard,  inventory  at   $19,775  02 


The  organization  of  the  force  employed  has  been  as  follows  : 

The  labor  gangs  have  been  under  the  charge  of  Mr.  C.  W.  Young,  as- 
sisted by  J.  D.  Irving  and  Jos.  Scheidecker.  The  carpenter  work  has 
been  under  the  immediate  supervision  of  Mr.  E.  D.  Pepper,  and  the 
mason  work  under  the  care  of  T.  G.  Douglas,  assisted  by  foremen  C. 
Lynch,  John  Cahill  and  Thomas  Kelly.  The  records  of  materials  re- 
ceived were  kept  by  Mr.  Frank  Brown.  • 

In  the  office  I  have  had  the  aid  of  Mr.  J.  A.  Kingsley  in  the  care  of 
orders  and  accounts,  of  Mr.  B.  G.  Lingemau,  as  draughtsman,  and  the 
very  efficient  aid  of  Mr.  F.  L.  Rowland,  in  the  preparation  of  working 
plans  for  the  last  stone  contract,  and  in  the  care  of  the  work.  All  have 
done  their  work  well. 

The  work  done  during  the  year  1876  is,  by  your  direction,  prefaced  with 
a  brief  description  of  the  structure  itself,  is  follows: 

This  is  a  mass  which  yhen  completed  will  contain  28, 8S3^  cubic  yards 
of  masonry.  The  amount  laid  during  this  year  is  11,005^  yards  (or  al- 
together 25,8974,  yards),  leaving  2,986  yards  to  be  set  after  the  cables  are 
made. 


104 


The  joints  in  this  masonry  have  been  found  to  aggregate  about  18  per 
cent,  of  the  total  bulk. 

The  whole  rests  upon  a  timber  grillage  four  to  seven  feet  deep,  the  top 
surface  of  which  is  at  the  level  of  high  tide,  and  a  little  below  the  level, 
at  which  fresh  water  stands  in  the  soil. 

The  outline  of  the  masonry  in  plan  is  rectangular.  It  is  widened  at 
the  rear  by  an  offset  of  five  feet  on  each  side,  made  at  85^  feet  from  the 
front.  These  offsets  serve  to  give  greater  mass  over  the  outer  anchor- 
plates. 

The  length  over  all  the  base  of  masonry  is  129  feet.  The  width  at 
the  front  is  106  feet  4  inches,  and  at  the  rear  116  feet  4  inches. 

The  rear  mass  is  solid,  with  the  exception  of  two  small  tunnels  14  feet 
wide,  and  29  feet  7£  inches  high  to  the  crown  of  the  arch. 

The  front  and  narrower  portion  is  divided  by  large  tunnels  into  three 
parallel  walls.  These  are  called  anchor  walls,  and  receive  the  pressure 
from  the  anchor  chains;  the  two  central  chains  being  buried  in  the  mid- 
dle wall,  and  one  of  the  others  in  each  of  the  outer  walls.  These  tuanels 
are  covered  over  by  semi-circular  arches  of  23  feet  span,  springing  from 
a  height  of  about  65  feet  above  tide. 

The  thickness  of  the  outer  walls  at  the  springing  is  12  feet,  and  of  the 
middle  walls  26  feet. 

All  of  the  faces  except  those  of  the  small  tunnels,  and  the  rear  faces  of 
the  large  tunnels,  have  a  batter  of  half  an  inch  per  foot  rise,"  from  about 
eight  feet  above  tide,  and  in  addition  to  this  there  is  a  wide  offset  (10  inches) 
at  22  feet  above  tide.  The  courses  below  the  battered  portion  each  step 
in  by  wide  offsets  all  around. 

There  will  be  a  cornice  at  top  similar  in  design  to  those  on  the  towers, 
of  a  full  height  of  12  feet  7  inches. 

The  top  surface  is  to  be  sloped  to  the  grade  of  the  roadway,  of  which 
it  will  form  part,  and  will  have  a  length  of  117  feet  and  a  width  of  104 
feet  4  inches,  and  94  feet  4  inches  at  rear  and  front  respectively. 

The  height  of  the  roadway  at  front  will  be  89.04  feet,  and  at  the  rear 
85.24  feet. 

.  The  external  corners  of  all  courses  of  stone  above  the  10-inch  offset  are 
granite  blocks,  with  a  bold  projection,  the  edges  being  chamfered  off  four 
inches  all  around  and  fine  cut,  and  the  surfaces  being  fine  pointed. 

The  cornice  and  curtain  arches  in  front  are  also  of  granite,  with  a  1£ 
inch  draft  around  each  stone  and  fine  pointed  surface.  In  addition  to  this, 
642  yards  of  massive  blocks  of  granite  weighing  five  to  ten  tons  each,  were 
placed  over  the  anchor-plates  in  the  first  four  courses  above  them,  and 
thoroughly  bonded,  so  as  to  make  the  full  weight  of  the  masonry  above 
available  against  any  lifting  of  the  plates. 

The  remainder  of  the  stone  used  were  limestofie  with  a  bold  rock  face. 

All  limestone  were  furnished  by  Noone  &  Madden,  of  Kingston,  New 
York. 

The  first  contract  for  granite  was  let  to  Beattie  and  Dresser,  who  filled 


105 


it  from  their  quarries  at  Stony  Creek.  Conn.  The  last  contract  was  with 
Mr.  Joseph  Brennan,  whose  quarry  is  at  Charlotteburg,  New  Jersey. 
The  stone  are  slightly  pinkish  in  color,  and  correspond  well  with  those 
from  Stony  Creek. 

Stone-setting  began  this  year  April  10th,  by  the  day  gangs,  and  April 
12th.  by  the  night  gang;  and  was  carried  on  as  rapidly  as  was  consistent 
with  sound  work.  From  May  16th  to  23d,  was  occupied  in  raising  der- 
ricks, being  a  less  time  than  the  same  work  has  at  any  other  time  re- 
quired. 

June  6th,  the  work  of  putting  up  the  centres  for  the  main  arches  began. 
This  made  it  necessary  to  get  another  hoisting  engine  in  position,  and 
from  this  time  all  the  stone  were  hoisted  at  the  front  of  the  Anchorage, 
and  run  back  to  the  several  derricks  by  cars  on  a  temporary  track  on  top 
of  the  masonry. 

By  July  13th  the  work  had  so  far  progressed  that  it  became  necessary 
to  discharge  one  dny  gang,  and  the  next  day  the  night  gang  was  dis- 
charged. 

August  9th  to  18th,  was  occupied  in  raising  derricks  for  the  last  time, 
and  placing  them  on  top  of  the  arches.  On  the  2 2d  all  the  stone-cutters 
were  discharged ;  on  the  28th  stone-setting  was  completed,  and  by  Sep- 
tember 25th  the  pointing  was  completed,  and  all  masons  discharged. 

This  part  of  the  masonry  has  cost  more  for  labor  than  that  done  last 
year  on  account  of  the  large  number  of  grooves  to  be  cut,  and  other  stone- 
cutting  made  necessary  by  the  anchor-bars,  and  the  bars  inserted  for  at- 
taching and  securing  the  temporary  cables. 

The  total  expenditure  on  masonry  forthe  present  year  (and  not  hitherto 
reported),  including  a  due  proportion  of  all  office  and  contingent  expenses, 


and  the  stone  stored  for  future  use,  has  been   $184,405,05 

The  amount  previously  expended  was   253,847,22 

The  amount  estimated  as  now  required  to  complete  the  An- 
chorage is   59,552.41 

Making  the  total  cost  for  everything  except  plates  and  chains  $4!»7, 804,68 

The  estimate  as  revised  last  winter  was   502,096.28 

Showing  a  saving  on  the  summer's  work  of   $4,291,60 

The  weight  of  anchor-bars  and  pins  bought  during  the  year  is  509.778 

pounds,  making  a  total  weight  of  1,069.673  pounds  in  this  Anchorage. 

The  total  cost  of  bars  and  pins  in  place  for  the  year  is   $34,469,26 

Amount  previously  expended  on  plate  and  bars  was   42,049,55 

Total  cost  of  anchor-bars  and  plates    $76,518,81 

The  estimate  of  last  winter  was   79,041,55 

The  saving  on  the  estimate  is  therefore   $2,522,74 


The  organization  of  the  force  has  been  essentially  the  same  as  that  of 
last  year.    I  have  had  the  continued  assistance  of  Mr.  F.  L.  Rowland  in 


106 


the  general  care  of  the  work,  and  of  Mr.  J.  Mulqueen  in  the  care  of  office 
accounts. 

The  materials,  tools,  derricks  and  engines  on  hand  at  this  yard,  and 
present  value  of  railroad  (not  including  stone  stored  for  future  use),  in- 
ventory at  $20,039.92. 

A  considerable  portion  of  this  value  will  at  the  close  of  the  work  be 
available  as  a  credit  upon  its  total  cost. 

The  settlement  of  the  masonry  at  the  close  of  this  year's  work,  as  meas- 
ured at  the  top  of  the  offset,  was  an  average  of  l£  inches,  and  remarkably 
uniform.  This  is  no  doubt  due,  as  in  the  case  of  the  towers,  to  the  slight- 
ly increased  compression  of  the  foundation  caused  by  the  increase  in 
weight. 

Respectfully  submitted, 

F.  COLLINGWOOD, 

Assistant  Engineer  in  charge. 

New  York,  Dec.  31,  1876. 


BROOKLYN  ANCHORAGE.  1875. 

Col.  W.  A.  Roebling, 

Chief  Engineer  of  the  New  York  and  Brooklyn  Bridge. 

Dear  Sir: 

I  would  respectfully  present  the  following  report  upon  the  work  done 
during  the  past  year  at  the  Brooklyn  Anchorage. 

Previous  to  the  time  of  commencing  work  for  the  season,  the  masonry 
of  the  Anchorage  (during  1873  and  1  874)  had  been  carried  up  to  62  feet 
2  inches  above  high  water,  26  courses  of  stone  having  been  laid. 

Work  was  resumed  April  6th,  and  the  masonry  has  been  brought  up 
to  78  feet  6  inches  above  high  water,  and  entirely  completed  (except 
some  pointing  and  stone  dressing),  as  far  as  it  can  be  preparatory  to  cable- 
making. 

The  masonry  laid  this  year  was  5,921  cubic  yards  (using  5,314|-  yards 
of  stone),  and  making  the  total  amount  thus  far  laid  on  the  Anchorage 
24,255  cubic  yards. 

Considerable  cutting  of  dimension  and  archstone  has  been  done,  in 
consequence  of  the  contractors  having  failed  to  deliver  stone  on  time. 
This  has  not  been  an  unusual  experience ;  and  although  the  cutting  has 
been  charged  to  the  contractors,  the  result  has  been  a  considerable  in- 
crease in  the  cost  of  the  work  in  consequence  of  its  necessarily  irregu- 
lar prosecution. 

Considerable  delay  was  occasioned  also  by  having  to  leave  large  holes 
in  the  masonry  for  the  insertion  of  the  seventh  set  of  anchor  bars,  which 
arrived  too  late  to  be  put  in  place  at  the  proper  time. 


107 


•  The  stone-setting  derricks  have  been  raised  twice  during  the  season, 
and  now  rest  on  the  arches,  in  proper  position  for  use,  as  they  may  be 
required  during  cable-making. 

The  total  amount  expended  upon  the  Brooklyn  Anchorage  to  date  for 
everything,  except  anchor  chains  and  plates,  is  $507, 220.74. 

The  expenditure  estimated  as  requisite  to  complete  the  masonry  is 
$02,482. 

The  5th,  0th  and  7th  sets  of  anchor-bars  have  been  placed  in  position 
during  the  season ;  also  all  the  bars  for  anchoring  and  holding  down  the 
foot-bridge  and  cradle  cable;  and  for  use  in  letting  off  strands  of  the 
main  cables.  AH  the  bars  of  the  remaining  sets  have  been  received  ex- 
cept 72  of  the  10th.  and  most  of  them  have  been  scaled  and  painted,  in 
preparation  for  placing. 

The  amount  expended  on  them  during  the  year,  including 

labor  of  preparation  and  insertion,  has  been   $38,335  22 

Total  amount  to  date,  including  $12,301.31  for  the  plates, 

has  been   83,295  93 

The  amount  required  to  complete  them  will  be   5,508  40 

CABLE-MAKING. 

After  work  upon  the  masonry  was  stopped,  a  shed  was  built  covering 
the  top  of  the  Anchorage,  for  the  reception  of  the  cable-making  machin- 
ery. The  drums,  wheels  and  other  machinery  are  now  in  process  of  con- 
struction, and  will  all  be  placed  in  position  early  in  the  spring. 

The  cost  of  these  various  items  has  thus  far  been   $3,300 

The  estimated  value  of  machinery,  tools,  stores  and  other 

movable  property  now  in  the  Anchorage  yard,  is   10,122 

Respectfully  submitted, 

G.  W.  IffcNULTY, 
Assistant  Engineer  in  charge. 

Brooklyn,  Dec.  31,  1875. 


Col.  W.  A.  Roebling, 

Chief  Engineer  New  York  and  Brooklyn  Bridge. 

Dear  Sir: 

I  am  able  to  report  progress  in  the  preparatory  work  for  cable-making 
which  you  have  entrusted  to  my  charge,  as  follows.  This  includes  mak- 
ing all  the  machinery  for  cable  work ;  getting  over  the  temporary  wire 
ropes,  and  making  the  cradles  and  foot-bridges,  and  placing  them  in  po- 
sition. 

The  cable-making  machinery  is  located  on  the  Brooklyn  Anchorage, 
and  it  was  made  on  the  same  general  plan  as  that  used  in  making  the  ca- 
bles for  the  Covington  and  Cincinnati  Suspension  Bridge,  with  some 


108 


changes  to  suit  local  requirements.  It  is  in  duplicate,  for  making  two 
pairs  of  cables  at  the  same  time,  and  each  set  is  constructed  so  as  to 
work  independently  of  the  other. 

The  several  parts  of  the  running  machinery  are  designated  as  follows  : 
The  driving  wheels,  the  guiding  wheels,  the  sliding  beveled  gears,  the 
counter  shafts,  clutches,  levers,  pinions,  segment  gearing,  and  the  tighten- 
ing pulleys. 

The  driving  wheels  are  two  in  number,  attached  to  upright  wrought 
iron  shafts,  which  run  in  cast-iron  boxes  set  in  the  masonry.  These 
wheels  are  eleven  feet  in  diameter,  and  six  inches  thick  ;  having  two 
grooves  around  the  edge.  The  guiding  wheels  are  single  grooved,  fbu. 
feet  in  diameter,  and  three  inches  thick.  Three  of  these,  with  a  driving 
wheel,  form  one  set ;  and  they  all  run  in  the  same  horizontal  plane  ex- 
cept the  centre  one,  which  is  inclined  the  thickness  of  the  rope.  They  are 
so  constructed  that  the  working  rope,  or  ''traveler,"  runs  on  the  end 
grain  of  the  wood.  The  traveler  is  so  arranged  around  the  driving  wheel 
that  the  bearing  surface  is  equal  to  one  and  one-third  times  the  circum- 
ference of  the  wheel;  and  this  friction  has  been  found  to  more  than  equal 
the  power  of  the  driving  belt. 

A  horizontal  wrought  iron  shaft,  3£  inches  in  diameter,  runs  on  the 
Front  street  face  of  the  Anchorage  masonry;  and  motion  is  given 
to  it  by  a  sixteen-inch  leather  belt,  ninety-eight  feet  long,  leading  from 
the  fly  wheel  of  a  steam  engine,  in  the  yard  below.  From  pulleys  on  each 
end  of  this  shaft,  8-inch  belts  lead  to  pulleys  on  two  short,  horizontal 
counter  shafts,  on  the  top  of  the  masonry.  On  each  counter  shaft  are 
two  sliding,  beveled  gears,  worked  by  a  clutch  and  iron  lever,  so  as  to  give 
a  forward,  or  reverse  motion  to  another  beveled  gear,  which  is  fastened 
on  the  lower  end  of  an  upright  iron  counter  shaft.  On  the  upper  end  of 
this  shaft  is  a  pinion,  which  works  in  gearing,  bolted  in  segments, 
on  the  top  surface  of  the  wooden  driving  wheel.  Each  set  of  ma- 
chinery is  fixed  in  a  heavy  timber  frame,  which  is  securely  fastened  to 
the  masonry.  The  8-inch  belts  run  loosely  on  the  pulleys,  and  the  ma- 
chinery is  put  in  motion,  or  stopped,  by  a  tightening  pulley,  worked  by  a 
lever,  without  stopping  the  engine. 

On  the  New  York  Anchorage,  each  traveler  runs  around  two  4-feet 
wheels,  like  those  in  Brooklyn,  placed  in  a  sliding  frame,  which  is  so  ar- 
ranged that  the  slack  in  the  rope  arising  from  its  stretching  can  be  taken 
up  at  any  time,  without  cutting  and  splicing.  All  of  these  wheels  are 
made  of  oak. 

Under  the  head  of  machinery,  we  may  also  include  the  drums  for  hold- 
ing the  wire ;  the  reels  and  traveling  sheaves.  There  are  32  drums 
placed  in  the  wire  shed  which  was  erected  some  time  since,  on  the  Brook- 
lyn Anchorage.  They  are  8  feet  outside  diameter,  1G  inch  face,  with  a 
depth  of  rim  of  6  inches.  Their  working  capacity  will  be  about  50,000 
lineal  feet  of  No.  8  wire. 

As  soon  as  it  is  known  what  the  diameter  of  the  coils  of  wire  will  be, 


109 


the  reels  for  holding  the  same  will  be  made.  The  "  Traveling  Sheaves  " 
which  are  to  be  used  in  running  out  the  wire,  for  the  main  cables,  are  5 
feet  outside  diameter.  They  are  made  with  six  light  wooden  arms,  radi- 
atiDg  from  a  wooden  hub,  and  a  light  wooden  rim  2  inches  thick,  in  the 
outer  edge  of  which  is  a  Y  shaped  groove,  about  1  inch  deep.  This  groove 
is  lined  with  galvanized  sheet  iron, which  projects  4  inches  beyond  the  wood, 
thus  making  the  groove  about  5  inches  deep.  The  outer  edges  of  this 
iron  are  stiffened  by  having  a  wire  rolled  into  them,  and  by  thin  strips  of 
iron  which  are  riveted  at  intervals  to  the  outside  of  the  V,  and  bolted  to 
the  wooden  rim.  Thirty-six  holes,  3  by  2f  inches,  are  cut  in  the  sides  of 
these  rims  opposite  to  each  other,  for  the  free  passage  of  the  wind. 

The  wire  ropes  are  17  in  number,  made  of  galvanized  steel  wire.  Taken 
in  rotation,  their  names,  sizes  and  uses  are  as  follows  :  Four  "travelers," 
f  inch  in  diameter,  spliced  into  two  endless  ropes  around  the  propelling 
machinery  before  described.  They  have  been  used  for  hauling  over  the 
other  ropes,  in  part,  and  for  hauling  the  buggies  back  and  forth ;  but 
their  final  use  will  be  to  carry  the  traveling  sheaves,  when  the  wire  for 
the  main  cables  is  run  out. 

The  next  in  order  is  the  "carrier,"  If  inch  diameter,  for  holding  the 
weight  of  the  heavier  ropes,  when  they  were  hauled  over  the  river. 
Next,  3  cradle  cables,  2\  inch  diameter,  for  supporting  the  cradles,  which 
will  be  described  further  on.  Two  foot-bridge  cables,  on  which  a  foot 
walk  for  the  use  of  the  cable  workmen,  will  be  laid.  These  ropes  will  also 
support  one  end  of  5  of  the  10  cradles.  One  l^-inch  diameter  auxiliary 
rope,  which  with  the  carrier  will  finally  be  used  to  assist  in  supporting 
the  foot-bridge.  Two  1^-inch  diameter  "  storm  cables,"  which  will  extend 
from  one  tower  to  the  other  below  the  roadway,  and  be  attached  to  the 
foot-bridge  cables  by  small  wire  rope  suspenders,  in  the  form  of  inverted 
cables,  to  prevent  the  foot-bridge  from  being  lifted  by  the  wind.  Two 
g-inch  diameter  ropes,  for  hand-rails  for  the  foot-bridge,  and  4  "  pendulum 
ropes,"  f-inch  diameter.  These  will  be  used  to  support  small  iron  rods, 
having  flat  leaden  weights  attached  to  their  lower  ends,  which  will  sepa- 
rate the  two  parts  of  each  strand  of  the  main  cable,  while  they  are  being 
laid,  and  prevent  their  entanglement  by  the  wind.  The  travelers,  carrier* 
cradle  cables,  and  the  foot-bridge  cables  are  in  position.  The  auxiliary 
foot-bridge  rope,  and  one  storm  cable,  have  been  taken  over  the  river. 
Attempts  have  been  made  to  attach  the  suspenders  to  the  storm  cable, 
and  to  place  it  in  position,  but  high  winds  and  extreme  cold  have  preven- 
ted this  from  being  done.  I  have  arranged  swing  stagings,  or  "  double 
buggies,"  to  run  on  and  between  the  two  foot-bridge  cables,  for  doing 
this  work,  and  on  trial  they  proved  well  adapted  for  it. 

The  difficult  and  dangerous  problem,  how  to  get  the  wire  ropes  across 
the  river,  and  over  the  streets  and  buildings  from  one  Anchorage  to  the 
other,  was  safely  and  expeditiously  solved,  in  the  following  manner: 

The  two  travelers  were  the  first  to  be  taken  over.  The  reel  contain- 
ing the  first  rope  was  placed  on  a  woodeu  axle,  in  a  frame  on  one  of  our 


110 


stone  scows,  at  the  foot  of  Brooklyn  Tower.  The  end  of  the  rope  was 
then  hoisted  over  the  tower,  and  drawn  down  into  the  yard,  where  a  Ma- 
nila rope  leading  to  a  steam  engine  at  the  Anchorage  was  attached  to  it, 
and  it  was  carefully  hauled  to  the  Anchorage  and  made  temporarily  fast 
there.  Fenders  and  trestles  were  erected,  and  men  were  stationed  on  the 
roofs  of  the  intervening  buildings,  to  protect  them.  The  operation  was 
entirely  successful. 

The  scow  containing  the  reel  with  the  remainder  of  the  rope,  was  then 
towed  over  the  river  to  the  dock  at  the  foot  of  New  York  Tower,  and 
the  bight  of  the  rope  as  it  unreeled,  was  allowed  to  sink  to  the  bottom. 
The  scow  was  made  fast  to  the  dock,  and  all  the  rope  on  the  reel  was 
coiled  at  the  foot  of  the  tower,  after  which  the  end  was  hoisted  to  the  top 
of  the  tower,  and  drawn  down  and  fastened  to  one  of  the  grooved  drums 
of  the  stone  hoisting  engine. 

It  was  at  first  supposed  that  the  ropes  would  have  to  be  hoisted  out  of 
the  water  on  a  Sunday  morning,  when  there  were  few  vessels  in  the  way; 
but  by  frequent  observations  I  learned  that  we  could  get  from  4  to  8  min- 
utes clear  water,  on  any  day  of  the  week,  and  it  was  resolved  to  make 
the  attempt  as  soon  as  we  were  ready. 

Engineers  Martin  and  McNulty  took  position  in  the  roadway  of  the 
tower,  to  watch  for  an  opening.  Foreman  Dempsey,  with  some  workmen 
was  left  on  the  top  of  the  tower;  while  I  clambered  up  on  the  hoisting 
frame  to  note  the  deflection,  with  William  Brown,  carpenter,  to  pass  sig- 
nals to  the  engineer  of  the  hoisting  engine,  when  to  start  and  when  to 
stop. 

A  tedious  wait  of  more  than  half  an  hour  followed.  At  last  I  heard 
from  Mr.  Martin  the  welcome  words,  "  Go  a-head  !"  and  passed  them  to 
Brown,  who  signalled  the  engineer.  In  a  few  seconds  the  rope  began  to 
move ;  there  was  a  ripple  around  it  in  the  water;  it  began  to  draw  away 
from  the  dock  toward  Brooklyn,  and  soon  we  could  see  the  other  part 
coming  from  Brooklyn  towards  us.  Faster  and  faster  the  space  of  clear 
water  between  the  two  parts  narrowed,  and  in  four  minutes  from  the 
time  of  starting,  it  swung  clear  of  the  surface  of  the  water,  with  a  spark- 
ling swish,  amid  the  cheers  of  spectators,  on  the  wharves  and  ferry  boats, 
and  the  shouts  of  our  own  workmen. 

Up  went  the  rope,  and  when  it  reached  the  level  of  the  roadway,  the 
engineer  was  signalled  to  go  slow,  and  the  speed  lessened.  "When  it  was 
within  a  few  feet  of  its  proper  deflection,  80  feet,  I  passed  the  word  to 
slow  the  engine,  which  was  done,  but  not  until  the  rope  had  reached  a 
point  somewhat  above  the  intended  deflection,  though  in  time,  however, 
to  prevent  any  damage  to  the  rope.  This  occurred  August  14th.  The 
second  rope  was  taken  over  in  the  same  manner,  on  the  same  day. 

These  ropes  were  securely  fastened  on  the  top  of  the  tower,  and  the 
two  ends  were  then  hauled  over  the  streets  and  roofs,  to  New  York 
Anchorage,  much  in  the  same  manner  as  in  Brooklyn.  The  ends  were 
next  spliced  together,  around  the  driving  and  guiding  wheels,  thus  form- 


Ill 


ing  one  endless  rope,  capable  of  being  worked  to  and  fro,  to  draw  loads 
and  to  carry  burdens.  It  is  arranged  to  run  in  wood-lined  wbeels  on  the 
towers,  and  although  it  has  seen  much  hard  service,  it  bears  no  percepti- 
ble marks  of  wear. 

The  two  parts  of  the  other  traveler  were  taken  over  by  being  lashed  to 
the  first  one,  and  then  carried  over  by  steam.  After  being  taken  over, 
the  ends  were  secured  on  the  two  anchorages,  and  the  lashings  were  cut 
loose  by  men  seated  in  "boatswain's  chairs" — rude  contrivances  much 
used  by  riggers — which  were  arranged  to  slide  on  the  first  traveler.  This 
somewhat  novel  feat  was  skillfully  accomplished  by  Timbs,  Supple, 
Cohne  and  Carroll,  on  the  first  rope.  The  second  was  cut  by  Miller, 
Arnold,  O'Neil  and  myself. 

The  carrier  was  got  over  in  the  same  manner  as  the  first  travelers — 
through  the  water.  The  tug,  in  towing  the  scow  across,  made  a  detour 
down  stream,  so  that  when  an  attempt  was  made  to  draw  the  rope  out 
of  the  water,  the  side  strain  was  so  great  as  to  pull  it  out  of  the  3-feet 
wooden  wheel,  in  which  it  was  running  on  the  tower. 

James  O'Neil  was  injured  at  that  time,  by  being  struck  by  a  piece  of 
plank,  which  was  thrown  against  him  by  the  falling  rope.  This  accident, 
I  am  happy  to  state,  is  the  only  one  which  has  happened  on  this  part  of 
the  work.  The  rope  was  replaced  in  the  wheel,  and  a  guiding  sheave 
was  put  on  it  outside  of  the  tower,  and  it  was  then  hauled  up  without 
further  difficulty. 

After  being  hauled  out  of  the  water,  the  end  was  taken  from  the 
grooved  drum,  and  hoisted  to  the  tower  again,  on  the  land  side,  and  fas- 
tened to  a  snatch  block  which  ran  on  the  traveler.  A  Manila  rope,  some 
300  feet  long,  was  made  fast  to  the  end  of  the  carrier,  and  the  block  was 
allowed  to  slide  down  on  the  traveler,  toward  the  anchorage,  carrying  the 
end  of  the  wire  rope  with  it.  It  ran  down  350  feet  by  its  own  gravity 
the  bight  remaining  coiled  on  the  dock.  When  it  would  go  no  farther  in 
this  way,  men  pulled  it  along  to  the  Anchorage  by  the  Manila  rope. 
There  a  tackle  was  attached,  and  it  was  strained  up  to  its  correct  deflec- 
tion, by  steam,  and  fastened  by  a  socket  and  stirrup.  I  found  it  lessened 
the  danger  and  the  labor,  to  hang  the  end  of  the  rope  to  the  traveler,  as 
above  described. 

To  get  over  the  five  other  large  ropes,  I  adopted  the  plan  which  I  used  so 
successfully  at  Niagara  Falls,  namely:  by  suspending  the  weight  of  the 
rope  to  be  hauled  on  the  carrier,  and  hauling  by  the  traveler,  or  a  Manila 
rope,  worked  by  a  steam  eDgine.  The  first  cradle  cable  was  hauled  by  the 
traveler;  but  this  plan  did  not  work  well,  owing  to  the  frequent  slip- 
ping and  breaking  of  the  belt,  which  transmitted  power  to  the  machin- 
ery. This  rope  was  landed  in  New  York,  and  it  cost  much  labor  to  get 
it  into  position  for  running  over,  besides  our  trouble  with  the  traveler. 

It  was  therefore  determined  to  land  the  remaining  ropes  at  the  foot 
of  Brooklyn  Tower,  which  would  bring  them  at  once  into  position ;  and 


112 


to  do  the  hauling  by  a  Manila  rope,  worked  on  the  grooved  drum  before 
mentioned.    The  operation  was  conducted  as  follows : 

The  Manila  rope  was  first  drawn  over  the  river  by  the  traveler,  and 
made  fast  temporarily  on  Brooklyn  Tower.  It  was  suspended  from  the 
carrier  by  small  clevises,  which  prevented  the  bight  from  dropping  in  the 
way  of  passing  vessels,  and  at  the  same  time  allowed  it  to  move  freely. 
These  clevises  were  put  on  80  feet  apart.  Another  rope  was  drawn  up 
from  Brooklyn  Anchorage  in  the  same  manner,  and  one  from  New  York 
Anchorage. 

A  stick  of  oak  timber,  6  x  10  inches  and  10  feet  long,  was  fastened  by 
stirrups  on  the  top  of  the  carrier  just  outside  of  Brooklyn  Tower,  on  the 
water  side.  To  this  a  large  grooved  cast-iron  pulley  was  hung.  A  14- 
inch  leading  block  was  also  made  fast  to  this  stick,  near  the  iron  sheave, 
and  through  it  a  4^-inch  Manila  rope  led  to  an  engine  on  the  dock.  By 
this  rope  the  end  of  the  wire  rope  was  hoisted  from  the  reel  on  the  dock 
below,  and  run  over  the  iron  pulley.  The  hauling  rope  from  New  York 
was  then  made  fast  to  the  end  of  the  wire  rope,  and  the  New  York  engine 
was  started,  and  with  the  aid  of  the  dock  engine  in  Brooklyn,  the  wire 
rope  was  hauled  10  feet  toward  New  York,  and  then  the  first  hanger  was 
put  on. 

These  hangers  were  grooved  iron  sheaves,  8  inches  in  diameter,  to 
which  a  pair  of  "  sister  hooks"  were  attached,  in  such  a  way  as  to  allow 
of  their  being  opened  and  slipped  over  the  carrier,  in  the  most  expeditious 
manner.  The  cables  were  lashed  below  the  hooks  by  i-inch  hemp  ropes. 
Thus  the  hauling  line  pulled  the  cable  along,  while  the  hanger  ran  easily 
on  the  carrier,  and  held  the  weight  of  the  cable  lashed  below.  The 
hangers  were  put  on  about  60  feet  apart.  The  oak  stick  was  used  to 
prevent  the  carrier  from  being  strained,  at  too  sharp  an  angle,  by  the 
weight  of  the  cable  aud  hoisting  line.  A  buggy  hanging  on  the  traveler 
was  used  for  two  men  to  stand  in  to  put  on  the  hangers. 

In  this  way  a  cable  was  drawn  to  the  New  York  Anchorage ;  a  line  from 
that  anchorage  being  attached  as  soon  as  the  end  of  the  cable  reached  the 
tower.  It  was  necessary  to  use  the  line  at  Brooklyn  Tower  to  assist  in 
lifting  the  weight  of  the  cable,  until  350  feet  had  been  run  out.  after 
which  the  New  York  line  did  all  the  work.  I  also  had  to  "  fleet  "  the 
New  York  line  400  feet,  on  the  main  span,  to  help  the  line  from  New 
York  Anchorage. 

TV  hen  the  end  of  a  cable  reached  New  York  Anchorage,  a  wrought 
iron  socket  was  put  on,  and  it  was  attached  to  an  anchor  iron  in  the  ma- 
sonry by  a  stirrup.  Meanwhile  the  end  remaining  on  the  reel  was  taken 
off  and  coiled  on  the  dock,  and  then  hoisted  to  the  top  of  Brooklyn 
Tower,  and  hauled  to  the  anchorage  by  the  line  before  mentioned,  the 
weight  being  held  by  hangers  on  the  carrier. 

The  cable  was  next  strained  up  until  the  hangers  were  relieved  from 
its  weight,  whsn  they  were  taken  off  by  men  who  went  down  in  buggies 
for  that  purpose.    The  buggies  ran  on  the  carrier,  and  were  hauled  back 


113 


by  the  traveler.  The  cable  was  strained  up  still  further,  to  the  required 
point  of  deflection  in  the  centre  of  the  main  span  ;  then  it  was  cut  off,  and 
an  attachment  was  made  by  a  socket  and  stirrup,  as  in  Xew  York.  On 
the  towers  the  cables  ran  on  two  grooved  oak  wheels,  3  feet  in  diameter, 
and  6  inches  thick.  When  a  cable  had  been  taken  over  and  fastened,  it 
was  lifted  out  of  these  wheels  by  powerful  screws,  set  in  a  strong  frame, 
and  lowered  on  to  permanent  oak  blocking.  This  plan  was  pursued  with 
two  foot-bridge  cables,  and  two  cradle  cables. 

Nearly  four  days  were  consumed  in  getting  over  the  first,  by  the 
traveler,  and  fastening  it;  while  the  last  one  was  drawn  over  in  less 
than  nine  hours,  and  fastened  in  less  than  five  hours  more;  thus  show- 
ing the  superioritv  of  the  last  plan  over  the  first,  and  the  increased  effi- 
ciency of  the  workmen  through  practice. 

The  cradles,  ten  in  number,  are  nearly  finished.  Those  in  the  main 
span  are  nearly  48  feet  long,  and  so  arranged  that  the  strands  of  the 
main  cables  will  be  within  easy  reach  of  the  men  who  are  to  regulate 
the  wires  The  four  cradles  in  the  land  spans  are  about  7  feet  shorter 
than  the  others,  owing  to  the  fact  that  each  pair  of  cables  will  be  14 
feet  closer  together  on  the  anchorages  than  they  are  on  the  towers.  The 
cradles  are  made  of  oak.  in  the  most  substantial  manner,  combining  light- 
ness and  great  strength.  They  are  4  feet  in  width.  The  centre  of  the 
floor  is  made  in  part  of  iron  rods,  so  as  to  admit  of  the  free  passage  of 
the  wind,  and  thus  reduce  oscillation. 

The  foot-bridge,  which  is  to  extend  from  one  anchorage  to  the  other, 
over  the  tops  of  the  towers,  will  be  made  of  oak  slats  3  x  l£  inches,  laid 
directly  on  the  cables,  with  2-inch  spaces  between  the  slats,  for  the  free 
passage  of  the  wind.  The  slats  are  held  in  place  by  longitudinal  strips 
3  x  1  finches,  to  which  they  are  fastened  by  round  clinch  nails.  When 
the  floor  is  laid  these  strips  will  lie  directly  over  the  cables,  to  which  they 
will  be  secured  by  U  shaped  stirrups,  plate  washers  and  nuts.  This  floor 
is  all  put  together  in  sections  of  12  to  16  feet,  and  as  soon  as  the  storm 
cables  are  attached,  it  will  be  laid. 

When  all  the  cradles  are  in  position,  each  half  of  a  traveler  will  have 
7  supports  between  the  anchorages,  namely:  one  on  each  of  5  cradles, 
and  one  on  each  tower.  Those  on  the  towers  will  be  made  of  3  wood 
lined  sheaves,  placed  a  short  distance  apart ;  those  on  the  cradles  will  be 
single  sheaves.  Numerous  wooden  rollers  will  be  required  for  the  guid- 
ance of  the  wire  when  running  out ;  but  the  position  of  many  of  these 
can  be  determined  only  by  actual  trial,  when  running  the  wire. 

The  carpenter  work,  blacksmithing  and  machinery  (of  which  I  have 
the  gen-  ral  supervision),  are  of  such  a  varied  miscellaneous  character, 
that  the  work  is  tedious  to  itemize  and  difficult  to  describe.  It  may 
suffice  to  say  that  a  great  part  of  the  work  in  these  departments,  during 
the  past  year,  has  been  directly  or  indirectly  connected  with  the  prepara- 
tions for  cable-making  ;  and  that  it  has  been  well  and  faithfully  done,  and 

8 


probably  as  cheaply  as  was  compatible,  with  a  due  regard  to  strength 
and  safety.  (Mr.  A.  H.  Smith  has  had  immediate  charge  of  the  machine 
shop  and  steam  engines,  while  Mr.  Downey  has  turned  out  excellent  work 
from  the  blacksmith  shop.) 

I  have  anticipated  much  trouble  in  instructing  inexperienced  men  in 
the  details  of  cable-making,  as  we  have  only  one  man  who  has  ever  seen 
anything  of  the  kind ;  but  the  intelligence  and  skill  displayed  by  the 
workmen  in  these  preliminary  operations,  lead  me  to  thiuk  that  I  may 
have  overestimated  the  difficulties  to  be  overcome. 

It  is  a  matter  of  history  that  the  river  was  first  crossed  on  one  of  the 
travelers,  August  25,  and  I  wish  to  state  here,  that  the  transient  notoriety 
attending  the  affair  somewhat  annoyed  me.  I  had  a  natural  desire  to 
cross  first,  but  my  principal  object  was  to  show  my  workmen,  who  were 
to  follow  under  more  dangerous  conditions,  my  own  entire  confidence  in 
the  strength  and  security  of  the  work. 

Foremen  Smallfield,  Dempsey,  Young  and  Cohne  have  rendered  efficient 
service. 

I  have  carried  out  your  instructions  to  the  letter,  unless  in  cases 
where  you  have  given  me  discretionary  power ;  and,  from  my  perfect 
familiarity  with  your  plans,  and  my  own  experience,  I  shall  expect 
the  cables  of  this  bridge  to  equal,  if  they  do  not  excel,  the  best  that  ever 
were  made. 

All  of  which  is  respectfully  submitted, 

B.  P.  FARRINGTON, 
Master  Mechanic  New  York  and  Brooklyn  Bridge. 


Brooklyn,  December  30,  1876. 


